First of all, welcome.
Please understand that, while our opinions may seem harsh, they are the voice of experience. No disrespect is meant to you or the the owner. Any Fiero that is undriveable, that is in unknown condition, or is setting on bare ground for who knows how long is suspect. Fieros hide underlaying issues because their body doesn't rust. The seller's comments make we worry more.
You want a good, solid car to start with. Several members have had to give up beautiful Fieros, because everything under/inside the body had rusted away. Just to look at parts prices, suppose that the following were needed:
Fuel pump - $30
Fuel sending unit - $200
Brake lines - $180
Fuel lines - $200
Coolant lines - $160
Rubber coolant hoses - $250
Brake pads/rotors - $200
Wheel bearings - $200
Tires - $400
Spark plugs/wires - $80
Vacuum lines - $180
Cruise cannister - $30
Alternator - $80
Battery - $100
Total so far:$2290 in parts alone
Then, it needs seat covers, headlight motors, a headliner the gas tank cleaned & repaired, the radiator fixed, various relays, sensors, etc. It'll need all the fluids flushed. Then there will be electrical issues, and you'll troubleshoot for bad grounds. Probably about this time, you'd discover that the frame is rotted away. Then the paint is still terrible. And the car probably still doesn't run. Then comes the engine/tranny rebuild.
I agree. Get a running car from a known member in the Mall. You'll get to meet the member. Hopefully, the member will tell you any issues with the car. Then you'll have only the same things the rest of us deal with.
In Toney, AL, there is a place called the Fiero Factory. You can probably get a decent car from Jeremy there.
Figure to pay at least $2600 for a decent Fiero. You missed a few for a bit less.
The issues to look for are overheating, any leaks whatsoever. Shaking, rust in the corners of the trunk under the carpet, visible rust under the car or in the wheel wells, odd electrical behaviors, or things that don't work. Oh, and make sure the frame is straight and the body panels lone up. If the car looks cared for, it may be, but the body is not the way to check. If the engine compartment is dirty or the body looks badly, leave it. If the body looks good, ignore that--it's just a bonus.
[This message has been edited by tshark (edited 10-22-2014).]