Cost to Sandblast a K-member
You said your compressor probably isn't up to snuff for a sandblaster, but do you have a friend who might? Do you have a Harbor Freight store nearby? Take a look at these items:
Hopper Blaster
Spot Blaster
Heck, for that matter, you could probably rent a large compressor for a whole day cheaper than the price you were quoted for having it blasted. Check out the local equipment rental shops. Gather up a pile of stuff you want blasted (maybe get a few friends needing some blasting done and everyone split the cost of the rental and the bags of sand) and do it all at once.
United Rental compressor
Time to get creative,
Jerry