That's what my budget was too. I started eyeballing them back in early Dec and just bought my diesel tow rig about a month ago now for that exact figure. You can find a few of the '94-'97 F250 & F350 4wd's with the 7.3 powerstroke in that range. You won't find any of the 24V cummins in there and I would only do a 12V if it was 4wd and MANUAL! The Auto's are dogs from first hand owners while the manuals aren't bad and with very reliable minor mods can be pretty good towers. I'm not a chevy 4wd chassis/suspension fan myself though so I didn't bother with the duramax bow tie deals...
Ive also been looking at selling my f-150 for a mid 90's power stroke. The pre duramax Chevys are dogs compared to the power stroke and cummins. The earlier ford international 6.9 is a great motor but no factory turbo. But banks makes a kit for them.
Not sure if it matters to you but if you're looking 4wd there's a pretty drastic difference in the front suspensions between the F250 and F350. The F250 is the goofy Ford TTB like what's under my exploder but it's on leaf springs instead of coils like mine. The F350 is a solid front axle on leafs springs. Some people don't like the TTB front ends, I'm personally embrace them and like them a lot. Personal opinion I think though... Something to keep in mind if it's of any concern and if you're looking for 4wd. If 2wd they'll be i-beam and all work/handle pretty well.
If you're interested in driving a powerstroke in general you're welcome to take mine for a spin for reference. I was looking at those exact models and then at the last minute ended up going the van route and picked up a '02 E350 powerstroke. I love it! I actually noticed a white one for sale for a decent price the other day.