PEQ Door and Window Sensors on eBay for $18 each.
http://www.ebay.com/itm/282024335177
These look almost identical to the SmartThings sensors, just have a different cover. Even come in the same packaging. They also are recognized as SmartThings sensors. I have several of their sensors from when BestBuy had them on clearance, work great.
No Affiliation, besides that I just bought some more.
I have a couple of these and they are huge. It’s an eye sore if you can’t hide it at your door or Windows but then again. That’s a nice price and thanks for sharing 
I have 2 PEQ open/close sensors, and out of 50ish devices, I’ve found then to be the least reliable (meaning they frequently drop from the network). FWIW, I have other ST and ecobee devices nearby the PEQ sensors and they work fine and with significantly greater consistency. Maybe mine are from a bad batch, but figured I’d share the experience.
Really ? I have the exact opposite results. I have a 1/2 dozen PEQ O/C and Moisture sensors and have never had one of them drop. They are on the basement doors and under the washing machines in the basement, so are actually the furthest devices from the hub. I am 99% certain they are the only devices that have never dropped off or had to to be reset since they were installed over a year ago. All but one are still on their original batteries.
I have probably 25 PEQ devices - mostly water sensors but a few open/close sensors. They are very reliable and have great battery life. Make sure you have a strong zigbee network.
I would buy more but I already have some open/close sensors I’m not using.
Ordering one to try out. Thanks for posting the deal.
They are made by Centralite, the same company that makes the ST sensors. And they will be recognized by ST as ST sensors. So you shouldn’t have any problems.
Here is a link to the old Best Buy sale, with way more information.
@RLDreams @greg @Aboxman Wow – I’m surprised to hear all the positive feedback on the PEQ devices! As if on cue, one of the open/close sensors dropped from the network late last evening and had to be reconnected this morning. Just checked on it again and found that it hasn’t been reporting temperature changes since reconnecting – hitting refresh in the ST app pulled in updated readings, but I wish the device would function normally and keep up-to-date like all the other devices.
On another note, the one that dropped last night is reporting 100% battery, which seems a bit suspicious. I’m going to try replacing their batteries this weekend to see if that does anything.
How strong is your zigbee network? Maybe try a repeater? The Iris plugs are a cheap repeater.
@greg I don’t have any quantitative measurements of the network strength (is there a way to do this?), but I can say the problematic device is about 15 feet away from the ST v2 hub with an obstacle free line-of-sight between them. In the same corner of that room I have a ST on/off outlet switch that works flawlessly and a GE link bulb in a lamp. The bulb has been flaky in the past, so I recently swapped it out for a spare and haven’t had any problems since. I generally assumed this issue was because the GE bulbs have that well-known firmware problem and it was independent of the PEQ sensor connectivity. But maybe there’s some unusual interference in that corner of the room that mucks up both devices…?
There is this.
But I would start here
Do these have the other capabilities of the ST sensors (vibration, etc)?
No, these would be like the original Open/Close Door/Window sensors, not the multi purpose sensor.
I think they have temperature sensor.
I’d suggest the interference is the GE bulb . Personally I would experiment with physically shutting off/removing the GE bulb , then rebuilding ZB mesh ( Power off hub completely for 20-30 minutes) let the mesh rebuild without the bulb. Then put the bulb back in service. That way the GE bulb should be at the end of that leg of the mesh and not in the middle, so any flakiness should be limited to that bulb.
I had an issue with my Gardenspots dropping , I also have GE bulb in one of the porch lights. I removed the GE bulb, let the mesh rebuild without it, then put the bulb back in and the Gardenspots have not dropped off since.
Very interesting thought… Things to try this weekend. 