Listen to the above poster lol. 330s are under 10g now and you get a complete car with everything in its proper place plus beefier suspension and brakes, etc.
2500 is most likely a bit of an underestimation as well, factor in labour, wiring, refreshing whatever you want to while its out like wear items, new mounting hardware... And then if you want to be even with a stock 330, factor in the estimated cost of bolting up suspension and braking (and probably more) parts from a 330..
You said you were worried about if your car would handle it -- that's a good way to think! If you're worried, get a 330 and sell your 323. You'll be much happier