if you do decide to go with the USB Microscope - QX5 MAKE SURE that you get the drivers for XP or you will be sorry. it will not work on your PC without these drivers. and they are almost impossible to get without buying another scope. I have a buddy that uses the QX3 and he gets very nice photo's but they are way over magnified. you do not need to look at a coin at 200X mag but some like it.they are mostly 60X-200X and to me that is looking way too close. if you cant see it at 6-20 X then it is not a big deal. most variety's can be seen with a reg 7-10X loupe. at 200X you are going to be seeing things that are not really there or are totally meaningless .I use a 10 30 X myself to get better pic's but you will get the best pic's with a 7.5 scope or you can get the whole coin in the shot anyway.
good luck and let us know the direction you take.
just my
Two Cents lol
Gary