I know much less about 3rd gens than I do 2nd or 4th gens, but two things leap out at me.
1: Condition. It’s in much more original condition and the overall condition is much better.
2: The vents in the hood make me wonder whether this is in fact a GTA?
And to add a third thing to that list...
3: You get what you pay for and if something seems cheap it’s often for a reason.
Running the reg number through the DVLA website to check the MOT history would be quite revealing.