I bought my 95 DX for $200 needing a motor. $500 got me a D16Z6 with the harness/ECU and a 5-speed trans and linkage all with ~80k miles on it. Bought a new clutch/flywheel from Autozone for around $150 and put it in. The only other "big" extra costs I can think of was the $60ish on new clutch hydraulics, $40ish on transmission seals/bearings, and the $55 conversion mount I needed because I went from auto to 5-speed. Of course this isn't necessary if you're staying with the same type of trans (auto-auto or 5spd-5spd)
Figure in another $100-150 or so for fluids, hoses, belts, plugs, wires, cap/rotor, etc.
Had it all done in a about a day and a half working by myself with limited tools. The hardest part for me was removing the shifter for the automatic and mounting the linkage in the tunnel and then running the clutch hydraulic lines. Again, most of the work involved for me was the trans swap part.
I'm no newbie to engine swaps though, have done dozens of third and fourth gen Camaro and Firebird engines and transmissions in the past.