All good advice.
As a general rule, I use CI per stick price from a box, then move onto Famous, and then onto a general web search, averaging the per stick price I find among as many sites I can find. Once you've done this for a while, you have a general idea of what cigars sell for. As I stated before, using B&M prices is not the route you should take, as taxes, markups, etc. vary wildly among different states and even different shops.
For limited or hard-to-find cigars, I use MSRP, factoring in availability. When all else fails, I check with another vet, the moderator, or both.