I reached 702 rwhp/667 rwtq with the following motor mods only:
replacement motor from an '03 Viper with Diamond pistons added - ~$8500 plus labor
Paxton at 8psi - ~ $6000 (already on truck when I bought it)
Roe water/meth injection - ~ $300 I think plus labor
Belanger headers, no cats, 4 dynomax mufflers, custom Corsa exhaust - ~ $2500 (already on truck when I bought it)
Paxton and X-metal heat exchangers - ~ $900 I think plus labor
custom tune(s) through Joe Donovan at Performance by Joe - ~ $400-500 I think
VEC3 - ~ $1000
DC Performance blower flash, custom Paxton intake system, thermostat - ~ $1850
I'd have to think about how much I've spent but I know I lost a boatload ever since the original motor blew up. Then add the X-metal Gen IV shifter, lowering kit, gauges, tach light, EBC green brake pads, QA-1 adjustable shocks, etc. Now I'm depressed