You can buy 250 cc dirt bikes on Craigslist if private sellers make them available. Finding a cheap dirt bike may take patience, some work and a bit of luck.
Frequently check the local Craigslist ads and listings in the area. Because Craigslist sellers only post items they are ready to sell, you have to check often for the dirt bike. It is wise to contact the seller as soon as possible and ask questions via email, phone call or text. Some sellers are willing to negotiate price but may be offended if an offer is too low.
Physically examine the dirt bike before making a purchase. Maintenance records and receipts for the dirt bike should also be included. Ultimately, it is up to you to ask questions and examine the dirt bike to feel confident in the purchase.