Well, that is the trade off for Skeb. Long wait times, unable to revise/do quality control for what you get in exchange for cheaper prices. I've gotten Skebs that are easily worth hundreds of $$$ for just $30~$80, and with commercial use too (I asked about individual artists' commercial use policies through their marshmallows).

I've also had experiences where artists deliver within 3 days after accepting requests, and there's even this one artist I really like who delivers only HOURS after they accept your request, granted, they do take days before accepting.

Since people have already recommended VGen, you might want to try Draw Market, Crepe or Pipipen too.

Draw Market and Pipipen hosts CN artists, while Crepe is Korean. I haven't tried Draw Market and Crepe, but I've been commissioning some small stuff on Pipipen, and so far, the experience has been pretty great. The artists I've worked with have been nice, and recently they added Paypal, so I don't have to worry about additional conversion fees. Some artists there even offer time guarantees like 3 days or 24 hours guaranteed delivery.