No, they do not charge. However, be prepared to wait a short while. The way Sprint SIM cards are handled is a bit different. Apple, will give you a SIM, but it's not like they will just hand it to you and you walk out.
Sprint pairs it's SIMs with the phone. The ICCID on the SIM and the IMEI/MEID/ESN on the phone have to match. That requires a process that they do in the back. So, they will need to take your phone from you to do it.
AJ's suggestion to go to the Apple store is the better one. It can take a month or more to get a SIM out of Sprint itself, even if you go to a store. Not saying it would take that long, but there have been reports of people waiting that long.