It's indeed delightful to encounter the gun you want and to be able to buy it on a whim.
Gao Yang and his friends were all in a good mood, but they were anxious waiting at the gun stall for his identity to be verified; they were eager to pay and move on. However, after buying a few more guns, the identity verification and registering of the gun numbers turned out to be quite a hassle.
Buying guns in America is easy and convenient, but there are many restrictions. To buy a gun, one must be an American citizen or a green card holder, have no criminal record, no drug abuse history, and not be wanted by the law or have a history of violence; only then is one eligible to legally purchase a gun.
The identities of Gao Yang and his friends were fake ones provided by Little Donnie, so of course, they had no negative records-clean as saints.