For "cheap" upgrades, and assuming you do not choose to go the nitros route, I would go with (in this order, having been through it)
K&N + smooth tubes. ~$100-200 = 5-15HP
Short shifter or shorter shift knob: $25-300. SVSI and B&M have short shifters, Rich Detert (sp?) sells a shorter shifter shaft, and MGW has beautiful shift knobs that also shorten the throw.
Muffler swap: You will be surprised how much HP you gain, and how much better it sounds when you get rid of the 28 # of back pressure in the stock mufflers. Go w/ glass packs (yes, glass packs) and you can likely stay under $100-200 depending on labor. = 10-25HP
Rear gear swap: you can buy a rear end from a Gen I OR 2 - both fit in the 94 - with gears of your choice already in it. Cost $750 - $1200 depending on how much time you spend looking for the rear end. You can then keep the stock rear end, or sell it to recoup much/most of your money. I went w/ 3.54, and am quite happy. = 0 HP, but feels like 35-50
Complete exhaust: Easy to spend $3k here. Probably better off spending some more and doing heads and cam instead. 25-50HP
Roller Rockers: $1500+ w/ installation. ~15HP
Heads and Cam: Heffner, DLM, Elite, BTR, Dan Cragin. At least $5k plus labor. 50-100+ HP
Blower: Roe, DLM, Cragin, Heffner, etc. $8k-$30k+. 150-500+ HP
That's my $.02