Wheelbuilding prices vary but I'm going to guess $50.00 per wheel plus parts would be fair. Rims cost from around $20.00 and up. There are lots of rims in the $50.00 to $90.00 range. Spokes are around $1.00 each unless you're looking for something special. That takes you up to around $130.00 per wheel fairly quickly.
If you're not too picky, you can easily find a pre-built wheel for quite a bit less than that.
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