Browse the websites of each supplier carefully. Check
YouTube channels and pay attention to the details: how a product is made, what materials does the supplier use and have the products pass crush-tests.
It’s more profitable to invest in high-tech products.
Make sure that escape room builders produce latest generation escape rooms, otherwise its easier and cheaper to build a “keys and locks room” yourself.
The best way to “feel” the quality yourself is to play games that were built by that supplier. Don’t hesitate to ask for client’s contacts. A good supplier has nothing to hide.
Check reviews from players on Trip advisor. Good quality games often receive a 5-star review. (The exception is a bad game master)