I expect after a lengthy trial, appeals, etc., once they no longer need them for evidence they will hold an auction just like they do for all the houses, cars, boats, etc. that they confiscate and they will go to the highest bidder at the auction.
If you are the only Bitcoiner at the auction (not likely) you would then be able to get them for a song.
Normal (physical) assets usually do go cheap on such auctions. What do they do with confiscated stocks and bonds? What about PMs? If they auction those off too instead of market selling I guess the auction price will at best be only a few percent south of the market rate (but I'm only speculating).