Do it all at once. Then you don't have to buy a new flywheel, flywheel bolts, clutch/pressure plate bolts, tranny ect. If you just get the full swap, all you have to do is buy the aftermarket mount, front tranny mount, do the pluming for the clutch system, put the clutch pedal, clutch master cylinder, manual pedal tree, and then drill hole for the linkage/mount them up and switch the ECU and your basicly done. Run your wires for VTEC, then get rid of the shift box and thats it.
Including the swap? If not than yea, $500 sounds reasonable for a conversion, that miught even be a little high. Thing is, it depends a lot on where you get the parts, around here I could pick them up for around $100 not including the tranny. And, are you you doing the work yourself? If so, you'll save a lot.