Powder coated around my area is 50-70 per wheel if not damaged and straight forward. Lot more durable than spraying apparently
Just remember if you are power coating the wheels you will need to remove the bearings, this adds to the cost.
My son has just had his wheels paint by someone who was recommended from a friend But they are by far not the best He got charged( well I did ) £110 If that’s cheap he will put up with them but if that’s on the money he should take them back
Painted mine myself, took quite a bit of prep time and probably about £60 of primer, paint and lacquer. Happy with the finish, shame my tyre iron slipped as I was refitting tyre though, oh well!!
Always take them to a reputable company, I’ve seen to many cheap jobs where the disc surfaces have been sprayed and bolt holes full of paint, to do it properly pull the bearings and fit new as they’re relatively inexpensive, somewhere like wheelhouse tyres do a great job.
one of the downsides with powder coating is they they can soften your wheels by over cooking, they do low temp powder coat but not many use it