Here in the D/FW area, we've seen a LOT of stores carrying inexpensive, chinese import generators. We're talking sub $300, sometimes sub $200. We were discussing this in the local ham club meeting, when one of our members said that those generators were generally aimed at contractors and had an engine lifetime of 400 hours.

The general idea is that contractor generators get stolen on a regular basis, so no point in buying an expensive one. They are cheap enough to get charged onto a single job, and if they outlast the project, they can be given away to an employee.

The club member's understanding was that the engine would not generally be rebuildable, as it'd be a really low cost design for which parts would not be available. I can't speak from personal experience on this subject.