Figure $1500-$2000 in round numbers if you're doing it yourself. More if you find someone to do it for you.
The real stumbling blocks are the "I might as well" issues. Such as "since I'm taking this all apart, I might as well_________" fill in the blank.
In my case I rebuilt the engine, changed to a D44 and HP D30, used NV3550 instead of an AX-15, a new radiator and heater core, all new clutch assembly with master and slave setup, and my list goes on.
You'll need welding skills or someone to do it for you, along with cutting and grinding. Figure that in, too.