M785 29er wheelset for $250 shipped at Merlin

[InertiaMan]

Pretty good UST wheelset for this price.

Shimano XT M785 29er Wheels - Pair - Free RT62 Rotors | Factory Mountain Bike Wheels | Merlin Cycles

QR only with no option to retrofit 15mm or 142x12. Also a bit narrow by contemporary standards.
Hopefully the freehubs have improved on the M785 versus M77x models.
I rode the predecessor (MT75) wheelset, and the wheel structure itself was shockingly durable, especially for its weight and 24 spokes. But I had freehub issues until swapping in an XTR freehub.

The included rotors are relatively cheap/heavy, but hey, they're free.

[GTscoob]

Damn these would be pretty nice cross race wheels if they'd hold up to my weight.

[InertiaMan]

I wouldn't worry about weight, unless you're REALLY heavy. I'm 210 and I rode the MT75 wheelset very hard on my Sultan for nearly 2 years, and I didn't have the slightest problem with spokes, rims, etc.

I would worry more about how (relatively) high pressure, narrow tires might behave on the UST rim profile. I'd choose some tires with a relatively tight fitting bead if I were you.