2nd biggest shows reliability, for instance iphone 12 has 99%
https://www.czc.cz/apple-iphone-12-128gb-green/301129/produk...
the biggest shop does inverse how many (1%) used warranty
https://m.alza.cz/iphone-12-64gb-cerna-d6216436.htm
this is worth checking before buying something because 97% reliability is for instance extremely bad compared to 99%, you are 3 times more likely to get faulty piece
there is also monopolistic price comparison website heureka.cz where you can check price history years back, compare all shops and set price tracking with notification covering pretty much all online shops