Anytime you take goats to the auction, you might as well figure that they will be going for meat. Our auction has an Easter Lamb & Goat sale the 2 weeks before Easter. Several meat buyers are there bidding against each other. Selling a week or two after the Easter holiday isn't going to bring top dollar.
You could have always bought them back if they didn't bring enough. You would have been out the commission and of course the possibility of bringing disease home. Our local auction usually has about 10 goats every week. During Easter season, there might be 100 goats there. If somebody has a goat with CAE or something else, it could very well spread it around all the goats there. (Certainly not the best way to get into raising goats!) I have only bought once from the auction - a buck for breeding purposes. I will NEVER do it again. No, he didn't bring anything with him to infect my herd, but I'm not going to take the chance.
Another thing to ask, is how "good" were these bucklings anyway? Would you have used them to breed your goats? If the answer is no, then you should have banded them before they left your property.
You have to realize that out of all the local does in your area that kidded, 1/2 of them were bucklings. It only takes one buck for breeding a whole herd, so there are alot of bucklings out there, that might have the genes to improve a herd, but you are competing against others for selling "stud" bucks.
Not to come down on you, but was the auction the last resort? Did you put a flier up in your local feed store, in your paper trying to sell them BEFORE you took them to auction? You might have been better off banding them, and selling them off in the fall to the meat buyers once they were bigger. Let them fatten up on grass all summer, give a little grain in the fall and sell them.