Buying DSLR, canon loyalty program, eBay?

Is it safe to purchase a DSLR camera from eBay? Or are most defective, have cheap parts, or missing parts, etc? Where would be an alternative (besides craigslist) to get a T4i or Nikon d5100 for the best price?

I still haven't decided between the two, but those are my top choices, I still have to go in store to see how they feel in my hands, but at my local best buy they are very expensive. I know DSLRs are expensive, but there's a price variation between stores, like with almost any product.

How does the Canon loyalty program work? I've read about it, but I don't quite understand, can I just purchase any old/used canon even if it doesn't work, and use the loyalty program to get a discount on a t4i or t3i? For instance, if I send them a Canon EOS rebel Ti for how much could I get a t4i in the trade? And do I have to give the camera with a lens or can it be body only? And would I get a better deal if the lens is included?

Thank you

Added (1). Am I supposed to have proof of purchased from the old canon camera?

The Canon "loyalty program" only works when you buy from an authorized Canon dealer.

"the customers can replace their old Canon cameras with the new refurbished Canon camera. This new camera that is being exchanged provides the customer with the 6 months of warranty." --- http://canonloyaltyprogram.org/

I have purchased 2, $2500 Canon video cameras from e-bay and one 5D from Craigslist. (To be fair, I ended up knowing both the seller and his camera)

The e-bay buyer protection is a degree of assurance, but you just have to think critically: What is their return policy, how many items have they sold, what is the story and do you believe it?

Craigslist is nice because the sales are usually in-person and local… You can see the item first.

The entry DSLR is a funny consumer item. A lot of people get really into them and want a better camera (often because of a lack of skill!) A lot of people get put off by them and want a simpler camera. And some people get higher-end cameras for a single trip or event.

I seldom get my camera gear at retail. Between cameras, lighting, and lenses I've saved about $5000. Sure, one or more could fail tomorrow… I'd either buy another (never needed to do) or send it to canon for repair without hesitation.