Hey guys, I'm looking at buying a 98 3.4 T100. The truck looks good enough, but:

it idles at about 2000+- when it's not in gear, and at about 1250 when it is. Previous threads seem to indicate that it's a throttle position sensor or even a spring in the throttle body itself, either of which I'm cool with fixing. My question is: What other common issues could the high idle be caused by? Anything that would be a deal breaker (like a really expensive part) to a broke college student?

Thanks guys,
TI