My $1000 bike has a motor built by Lifan, a factory that churns out 10,000 motors per day. I bought direct from the importer and he assembled it for me as well (comes in a crate). The importer will sell me a new motor if and when I need one for a lot less than I paid for the bike.
A couple of buddies and I put together a group and bought 6 for 1K each. Importers website is
www.X-rage.com. He sells scooters ATV's and other rigs as well. See
http://www.alvatrading.ca/xr_qty3250.htm to check out the bike I bought.
I have a half dozen rides on it now (+-10 hours) and it runs like a champ. On close inspection you can tell the fasteners, pegs, etc are not great quality and its heavy.