Where to buy used gear?

Hey guys you've all been helpful in helping me pick which body i should get so now its time to actually buy it!
I was wondering where everyone buys their gear, originally I was going to go with Craigslist for the body (5D3) but my friend was actually trying to sell a Note 3 on Saturday and got robbed at gunpoint (in public) so i don't really want to walk around with $2xxx in cash.
I've looked at Adorama and B&H for their used bodies and lenses but they're pretty high. I've also looked at Lens Authority, which is part of Lens Rentals and they have nice prices but I was wondering if there were any other reputable sites I could look at.
I'm also looking for a Sigma 50mm and a Canon 24-105mm, I don't mind getting the Sigma new since I hear they have focus issues and i might need to try a few times until I get a good one. I'm just worried that if I buy a used lens their might be a scratch on the lens or dust.
Anything helps thanks guys! I've got bad experiences buying from electronics from eBay but if anyone has any reputable sellers I would love to know as well!