I have a 12 year old ITT Simon alarm system with much smaller window /door sensors that had batteries lasting literally 5+ years. I am brand new to the smartthings scene (still in the box), but feel the available zigbee or zwave sensors are bigger and drain batteries quicker. Also, I have 26 doors and windows and my eyes are popping out on the prices and lack of bulk purchasing options. Am I missing something?
Which model sensors? The Simon sensors I’m aware of are pretty much in the same size range of typical zwave and zigbee sensors:
http://www.interlogix.com/intrusion/category/wireless-sensing
The one exception is their Micro Sensor line, but the NYCE sensors that work with SmartThings are about the same size, maybe even a little smaller.
And the fibaro motion sensor, at one and three-quarter inches across, is smaller than anything that’s a motion sensor in the Simon line that I’m aware of. Granted, that one’s expensive.
The Lowe’s iris zigbee motion sensor is almost as small and can often be found on sale for about $20. Again I don’t think there’s a motion sensor that small in the Simon line. The Lowe’s is on the left in the following picture, and the SmartThings motion sensor is in the middle. The right is the same size as a typical Simon sensor.
http://www.lowes.com/pd/Iris-Motion-Sensor-Works-with-Iris/999925310
Wireless tags from Kumostat also work with SmartThings through some community written code and are very small, very nice devices which work well as door sensors. But again on the expensive side.
Bulk Buying?
As far as bulk pricing, that’s a little more complicated. The Simon system, of course, is typically sold by companies that require a monthly service contract, so they can afford to subsidize the individual devices somewhat.
With Smartthings, you’re not usually paying a monthly fee and you’re buying most of the devices from third-party vendors, so you have to carry full weight for the price. It’s like the difference between getting a subsidize cell phone from Verizon and buying one at Retail.
So you’re right that many security system vendors sell the devices more cheaply, but it’s not because they’re proprietary – – it’s because they’re making it up in the monthly subscription fee, just like the cell phone companies.
You may be able to get a volume discount at Lowe’s on the iris devices if you check through their contractor desk.
But you can still find some volume discounts if you shop around.
www.zwavedevices.com Will also often given volume discount, you can check with them if they have a particular model that you’re interested in.
Kumostat has a 20 pack Price on some of their sensors that typically runs around $399, although it depends on the model. But you also need to buy their bridge which costs about $60. So their bulk prices are around $23-25 per sensor depending on the exact package. You can typically get the iris devices for less on sale.
Other than that, you just have to look at the total annual cost and shop around for bargains. Several of the online specialty retailers will give you a bulk price if you’re buying at least a dozen of one model, but you usually have to ask about it.
If you can be more specific about the use case you’re looking for, including the budget, we can probably help more.
For example, one of the recessed door sensors won’t show at all since it fits inside the wall, and you can sometimes get a bulk price on those.
One of the strengths of the SmartThings system is the number of different devices it can work with, so if you have a specific use case in mind we can probably help recommend some possible devices. 
6 Likes
I don’t have the best answer for you, but… SmartThings is having a 4th of July sale right now. Everything is 20% off and you can use another code to get an additional 10% off.
Bulk SmartThings (sort of)
I should also mention that there’s a deals category in the forum here in case you haven’t found that yet. You can often find excellent discounts there. 
https://community.smartthings.com/c/devices-integrations/deals
Just be warned… Some community members have found the deals section a little, well, addictive. 
5 Likes
These are sensors I comparing to.
Thanks for all the replies. I guess I was hoping to spend less on sensors, but maybe it is what it is. Still trying to figure out exactly what I want to do with my ST…
The least expensive sensors will probably be the iris brand from Lowe’s, model 3320-L, once you stack a few coupons and deals. Some people have reported getting an individual device that runs the batteries really quickly – – if that happens just exchange it at the store.
You can talk to your local Lowe’s store and see if they can get you a discount price if you’re buying a couple of dozen, but otherwise just watch the deals category as these are very popular devices and community members post deals whenever they happen.
They are going to be longer than the ones you have now by about an inch, but they’re not gigantic.
http://www.lowes.com/pd/Iris-Contact-Sensor-Works-with-Iris/999925302
Note that only the second generation Lowe’s Iris zigbee devices are compatible with SmartThings. The ones in the purple box. The first generation zigbee devices are not compatible.
(Most zwave devices will work with SmartThings. For zigbee, look for devices that are certified for the “zigbee home automation profile” (ZHA 1.2), not just “zigbee.” The zigbee standard allows for multiple profiles, and they are not all compatible with each other.)
The quirky “tripper” open/close sensors made for Wink will work with smartthings and are a little smaller than the iris sensors, but the model has been discontinued and they’re getting hard to find. Your local target or Home Depot may have some on clearance, in which case they’re usually a good price. But the online prices have been going up since quirky went bankrupt so they now generally cost more than other sensors. I wouldn’t pay more than $20 each for these, but if you see them for less than that, I’d definitely consider them. (They’re usually sold in a two pack)
Smaller, not smarter. 
1 Like
Wow. Reading comprehension 101.
1 Like
Well I definitely didn’t want to spend so much, but thanks to your replies and searching mysel, I realized that I wasn’t going to get super cheap… So, I did in fact take advantage ofssmartthings4th of Julysale. They have ddiscountedbulk sensors of 5 pack. WWith bulk pricing and 20% sale and 10% coupon…i got the multi sensors for $25 each . Lets hope it works out. Thanks again.
1 Like
That’s a good price!