I've considered selling mine because sometimes I would like something a little more refined
Luxuries like power windows/locks, and air-conditioning are sweet to have, as well as plastic that hasn't changed color from age and everything else falling apart...
But, I'll keep it. After all the work I've put into it (so far), it's really not worth the effort to sell for a month's pay. I know I'd want one again down the road and finding a clean one is getting to be a bigger pain in the ass every day.
Keep it and just save some cash for a beater.