I don't have any for sale right now, but I might suggest Discovery Cruises $1s. They can be found in playable quantities, and in good-to-excellent condition.
If I was looking for the best blue $1s, I could find, I'd find somebody to harvest a vegas rack for me. Garden City is the only cheaper option that jumps out right now.
My understanding (from when I was after a few racks) is that they're a somewhat difficult one to harvest. Granted I wanted them in like-new condition, which made it that much more difficult, but it's still a pain since there's no poker room and you can't buy them at the cashier.
Bellagio chips, in contrast, were about as easy as it gets to harvest. Just buy them at the poker cage. I even sorted a couple racks to cherry pick the nicer ones at an unused poker table in front of the cage and then turned around and returned the ones I didn't want. No one seemed to care.