To be fair to Mahrez, he was a lot better than Michu.
Mahrez was the key player in a team that won the title, and was the best player in the PL.
Michu was the best player at a mid table club that wasn't challenging for anything, other than avoiding relegation.
Mahrez might not be world class but if we are looking to replace Sanchez, we aren't going to attract anyone much better than him, especially without CL football.
If we could get him, as well as Mbappe or Lacazette and Lemar, it wouldn't be the worst window we have had.