Keep the XTR crank (it's 9 speed, but will run a 10 speed chain fine) till the chainrings are worn, then replace. The XTR won't look too out of place, unless you intend to run 1x10 or 2X10, then it's no good. The major issue with the crank, and the reason for dumping when worn, is the chainrings on that generation are a non-standard pattern, and replacement, if you can even get them, will cost similar to just getting a new crank.

If you are looking to keep your budget in check, why not look at SLX, almost as good as XT at a significant cost reduction.

The only thing you haven't mentioned, is the frames BB spec, as this will determine if you can run a HT2, or if the BB is BB30 you can't without adapters.