If it's in a state which has such a law, yes. Otherwise, no.
If you mean the "Brady" bill, it did several things; mainly, it required a 5-day waiting period for gun purchases.
Gun store, gun show, on line.
Sometimes a gun show can be cheaper, sometimes a sale at a gun shop can be cheaper. You really need to shop around to find the best price. Be sure you are comparing the same model, and with used guns, be sure that you are comparing guns in the same condition.
The basic answer is no. The short answer is, a felon cannot have access to guns, and at a gun show, a felon would have access to guns, so it's illegal.
Library, gun show, gun shop, on line
Gun store, gun show, pawn shop.
BLue Book of Gun Values
There is no waiting period. If you pass the background check, which usually just takes a few minutes, you can leave with the gun right then.
There is no national waiting period since the instant background check years ago. In most states, you can go into a gun store, buy a gun and leave with it within a few minutes.
Sometimes, not always.
In some states there is waiting period and you have to get a permit for each gun so I would think 2-3 in a month depending on how long it takes to get a permit.
Gun shop, want ad, pawn shop, garage sale, gun show