Europeans of this sub, what are your go to frugal shoe options?

I used to buy a pair of Adidas sneakers twice a year one for hot weather and one water proof. Also I'm 10 kilo overweight and have lower back pain and most really cheap shoes like 30-40€ ones i tried hurt my back when i wear them for a while. I live in Serbia, I have a cousin in Vienna(obviously lol) who can get them for me if they don't seel them here.