Well, gotta thank you guys for helping to steer me in the right direction. Instead of paying more than $100 for a new wheel, I ended up paying about $10.
I opened the hub, cleaned it out, saw no noticeable signs of wear on the inside, but saw scores and pits on both the cones and the bearings. In fact, one bearing, that I noticed, had a torn shell. Needless to say, the old grease had tiny shards in it. I used Polylube to repack fresh new bearings. The shop said I was lucky they found the right cones for the bike.