32 hole LX hubs, M517 rims, 14/15/14 double-butted spokes, alloy nipples. You should be able to find a wheelset with this spec under $200 hand built. Unless you are >200 lbs. 36 hole is overkill.
Many of the big mail order houses offer custom built wheels. For example, Colorado Cyclist lists an XT hubbed, 517 rimmed custom built wheelset for $198. Mavic Crossrides from the same catalog are $299.90 for the set.