For me, I went with a Prorock D44 vs. upgrading the D30, for a few reasons.
The PR44 was $5500 to my door. That was with RCV's, ARB Locker, Synergy BJ's, a new yoke, 4.56 gears, Synergy High Steer Brackets and Reid Knuckles. That was with no tax, and free shipping with the axle built and ready to bolt up. (ordered from NR4x4)
For all of those parts for the D30, you are looking around $2600-2800. Lets assume you arent regearding as you stated - you will still need to install everything. Lets estimate that you will pay $300 for labor - just for the locker install and you do everything else yourself. You are at $3100 for parts. Now add the cost of a truss and gussets, installed (assuming you arent a welder) - you will be somewhere in the realm of $4,000 after tax and labor and all that.
My PR44 was $5500, and I sold my D30 for $800 bringing the cost to $4700.
For me, the $700 is well worth the additional strength, caster and steering geometry correction.
Or install a locker in a D30 and run it till is breaks.