Oh ya, the Zilla is cheaper.
Zilla
$2500 Purchase Price Zilla
$1000 Pipe
$150 Modified Stock Carb
$175 Intake System
$175 VF2 Reeds
$4000 and you would have a pretty fast machine - Figure 55-60HP rear wheel. Of course doing this will now start having the other parts of the engine be under more stress and will fail, so that is why getting the reliability mods is a must do in my book. I don't like going back to camp on a strap!
Modern 4 stroke
~$4500 for a clean 700 Raptor (38 HP engine stock)
http://orangecounty.craigslist.org/mcy/3348799707.html$900 Barkers Dual Exhaust
$250 FCI Intake System
$300 PCV Fuel Programmer
$200 Hotcam II or such
$6200 and you have a good Raptor (~55 Rear wheel HP)
You really need the aftermarket cam in the Raptor because the stock one sucks and stops making power around 6K RPM.
Beyond these levels, you start spending 1k here and 1k there and it adds up quick.
IMO The 700 and the Zilla stock suspension are pretty darn good (at least for Glamis dunes). You want to go faster riding, then spending money on the suspension first will be a good starting point.