Jim, yes, everything seems to cost more than planned...I am well over budget at this point, but they keep selling stuff to me
The timing and end-goal matters since it will determine how long you can live with certain things and whether you go for the incremental approach of upgrades/repairs versus the fully committed approach of never building/buying the same part twice.
As an example, suppose you currently have 33's on a D30/D35 setup with 3.07 gears running open/open (hard to imagine...right). Now suppose you decide you want to run in the hardcore group within 6 months and go to 35's within 18 months. You really should have a lockers in front and rear to run with the hardcore group, so let's assume you will get lockers to handle that situation. It is highly suggested that you not invest time, nor money, in the D35 and it is known that 3.07s with 35s will be miserable (I recall it being miserable with 33s). Research indicates a locked D30 with stock shafts will not support the 35s, so plan on an upgrade up front too. Additionally, there are mixed message on the Internet regarding the ability for the D30 standard carrier to support a lunchbox locker and 35s, so we'll assume you need a full case locker. Here are possible options to deal with this plan, based on the approaches mentioned earlier:
Incremental Approach:
1) Lunchbox locker in D30 (Labor = your time; Parts = $250)
2) Super35 Kit in the rear with lunchbox locker (labor = your time; Parts = $750)
3) time passes, fifth gear on the highway is still a distant memory...12 months later move on to #4
4) Regear D30 to something in the 4.xx area with a full case locker; perhaps upgrade to high pinion D30 while you are doing upgrades; upgrade axle shafts to chromoly (4.56, 4.88) (labor = $400; parts = $1350)
5) Acquire new rear axle, new mounting brackets, new locker, and regear it to same as D30 (4.xx) (Labor = $800; Parts = $900)
6) Sell used Super35 rear setup to recoup some of the cost of the new axle setup ($300???)
7) Sell used D30 lunchbox locker ($100???)
8) Buy new 35" tires ($900)
Fully Committed Approach:
1) Full case locker in the D30 with regear to 4.xx; upgrade axle shafts to chromoly (Labor = $400; Parts = $1350)
2) Acquire new rear axle, new mounting brackets, new locker, and regear it to same as D30 (4.xx) (Labor = $800; Parts = $900)
3) time passes, you are loving the pep of the 4.xx gears in the meantime...12 months later move on to #4
4) Buy new 35" tires ($900)
EDIT (Questionable when written):
Here is where you can start getting dividends on your investment...if you can time the belly up with the rear axle build, you can possible avoid having to buy adjustable control arms to support the pinion angle adjustment need by the SYE and new drive shaft. I stated "possibly avoid..." because based on my experience, the work to make the drive line vibration free without adjustable control arms would have to be fantastic (i.e., a true professional) since the slightest bit of incorrect angle adjustment will cause a vibration.
It should also be noted that with the 35s you should upgrade the brakes and steering components.
With unlimited budget, you should strongly consider becoming fully committed, but it is understandable to go incrementally towards your ultimate build goal.