Many bluetooth buttons including camera controls, media controls, and Flic buttons will integrate with Tasker. As you noted though, one of the concerns with this approach is the button is directly tied to whatever tablet or mobile device you have the button paired with.
If you have a dedicated tablet used for this purpose, then this isn’t an issue. For example, if you had a tablet dedicated to SmartTiles like @JDRoberts mentioned, you would be good to go. But if you plan on connecting the button to a mobile device (like your cellphone), keep in mind the impact this would have in usability for other users who might press the button while your phone is away.
At least one user has used the Satechi buttons which go for around £20.
Satechi bluetooth button or iBolt button and Tasker . Ideas/help welcome
I wouldn’t be surprised if you could get one of the cheap selfie camera buttons that only cost a few quid to work too. I haven’t personally used the button you linked to on Wish, but it’s fairly cheap if you wanted to try to buy one and give it a try.
The other challenge with bluetooth buttons is they often don’t provide the look and feel many users are looking for. That being said, a number of people are swooning over the Flic buttons which cost ~$40 shipped, so there are definitely others out there who like them!
The other approach would be to look for a Zigbee or Zwave button that meets your needs. There are plenty of wallplate buttons and switches, but as you mentioned they often start to get a bit pricey.