Summarize this article:

Typewriters on eBay are traditionally cheap because many eBay sellers don't know much about typewriters. However, these auctions can also be a gamble because there is no guarantee of condition. Oftentimes, the seller does not even know how to tell if a typewriter is in good condition or not. If you purchase a typewriter from an unknowledgeable seller, make sure they know how to properly pack their typewriter. The typewriter should be placed in a box with 4 inches (10 cm) of space on every side, and then filled with bubble wrap, foam plastic or shipping peanuts. The carriage release lever should be rubber banded down so that the carriage can slide left. This prevents damage to the escapement which is a sensitive mechanism deep inside the machine. The cast iron on Standard sized machines is easily broken in shipment if not properly packaged. Etsy sellers may be in the habit of selling multiple typewriters, and should therefore be able to provide better information about the typewriter quality. However, Etsy sellers may be in the practice of purchasing cheap typewriters and reselling them at a higher value, so be prepared to pay more on Etsy. Online websites like http://www.typewriters101.com, http://www.vintagetypewritershoppe.com, and http://mytypewriter.com are great options because they can tell you about the typewriter condition and tend to price typewriters fairly. You can also find a wide variety of typewriters on these sites, so if you have a particular typewriter in mind this might be your best bet. Ideally, your typewriter vendor will have a full or partial return policy. This helps cover you in the case of a poor-quality product or one that was damaged in transit.

Summary:
Monitor eBay for cheaper typewriters. Try Etsy for more knowledgeable sellers. Buy from a trusted online seller to guarantee quality. Check the return policy before you purchase.