All my previous experience has been situations where I dropped off my racquets at a club shop or downtown pro shop and picked them up later. They provided the strings. I am now playing in a town in florida. I'm not impressed by the stringing service at my club. There is a shop in town that advertises MRT stringers. I talked to them and they actually said they didn't carry too many brands of string and gave me a price for using my string, which they seemed happy to do. They also said i could get an appointment and have it done while I waited ( and hopefully watched). This last feature is important to me, as getting back and forth is a hassle. My question is whether or not it is appropriate or expected to tip the stringer. If so, how much for a $20 string job? I will be using BHBR which I know is a pain in the neck to string, so I think a little extra to the stringer is not unwarranted, but I don't want them to feel I am bigtiming them or whatever.