Shouldn't buy a used iPod, you'll have a hard time getting support / warranty for it.
For anyone else browsing, this is how it works.
When you purchase the iPod, it includes;
a 90 day eligibility for a single incidence of technical support by phone
a 180 day service agreement that covers any shipping charges for repair
a 365 day hardware warranty that covers defects and hardware failure
Technical support = $49.00 an issue
Shipping charge = $29.95 per repair
Battery replacement = $99 per battery after warranty expires
If you're a student, however,
AppleCare Protection Plan for Students; $47;
Unlimited Tech Support for 2 years
Service Agreement for 2 years
Battery replacement program for 2 years
So if you buy a used iPod, or have already purchased a used iPod;
Call Apple and get the APP; It'll save you money later.
800-SOSAPPL.