Fixing my son's newly bought second-hand bike. This is probably his last intermediate bike until I can buy him a brand new adult-size bike that will accompany

Fixing my son's newly bought second-hand bike. This is probably his last intermediate bike until I can buy him a brand new adult-size bike that will accompany him after that. The rear wheel seems to be quite badly out of alignment. Part of it is bent to one side for about 1 cm and after fixing that down to 1 mm or less by trimming the spokes, there's still considerable vertical misalignment left. Due to the horizontal misalignment the spokes and nipples don't have equally distributed configuration reserve, so it's pretty difficult to compensate against the slightly oval shape of the rim. While it's fun to fix things, I think I'll just go for a new wheel. Other than that, the bike was a good find. The power transmission was in good shape (chains and gears ok, the derailleur and the gear changer work ok, ball bearings are ok) and it worked out of the box. I only replaced one braking cable and repainted one section of the body, and I think I'll go with that. Oh, I paid 15€ for it, and the good old ones are of a ten-fold better make than the cheapest bikes you can buy new.