It really depends what the cards are. You could easily have spent $450 on a card 18 months ago, that would get slaughtered by a $100 card now, but it depends. If you're getting quoted $79, then it's probably a GeforceFX 5200 or Radeon 9200. Find out(if you can) what the card is he is proposing, and what card you have now, and i(or someone else here) can tell you whether you're going up or down.
Actually it sounds like maybe you have an original PCI(not-express) card. in which case, yes, anything new will whip it.
Josh Osborne - Central Innovation
HP Zbook Studio G4 - Windows 10 Pro, Intel i7 7820HQ, 32Gb RAM, Quadro M1200