Taking a few minutes to research before buying can save a lot of money and frustration. From my experience, communication with the store can tell you a lot. I think it is better to build a small collection of reliable products than to buy random cheap things.
If anyone is interested in real user experiences, I sometimes write short notes about the shops I test.
You can find one of the pages here:
check this link
Each material has advantages and disadvantages depending on season and activity. Some charts are very generic and do not match real measurements at all. I try to look for real photos of the insoles and soles, not only the outside of the shoe. Online shopping will always have a bit of risk, but experience makes it easier. Loose hinges make the glasses slide down the nose again and again.