It's easier to learn to rewick first, then recoil.
There's no way I'd buy premade heads (not that any device I use these days takes them asides from a few backup Protank2/Aerotanks/T3S) any more - they end up costing almost as much as some people spend on
juice!
Rebuilding them is great as it saves loads of money, and you can get the vape perfectly to where you like it.
I think that vape companies like Aspire/Kanger et al saw the
tank business like the disposable razor racket - sell a relatively inexpensive tank (razor) and then clean up afterwards selling heads (razor cartridges) to a captive market.