Hey I'm considering buying this 1994 2500 cummins I stumbled across for about $5 grand.  I'm just wondering if anyone has any advice on this and if that seems like a fair price if its in good condition.  Thanks.  

Really depends. I've routinely seen Cummins running strong well beyond 200,000 miles, but any engine or truck could be garbage if it's been abused or neglected. I'd definitely try to take a look at it in person if you can, ask lots of questions, and drive it.  

Drive it to a mechanic you trust. any used truck will need minor work.
I bought a 96 12 valve 4x4 with 88000 miles and drove it
back home pulling my jeep on a trailer across 5 states.
i work on my 4x4's myself and know what to look for.
the 12 valve is the best engine out there.
good luck.