Fremen did say 37 wasn’t enough. So I figure when they said “at least 61 keys” they meant it.
Sniping’s a fact of life on eBay. The present high bid often has nothing to do with the final selling price even a minute before bidding closes. You can bid the maximum you’re willing to pay and hope for the best; you might do better by using a sniping app yourself; but unless you get very lucky, the apparent bargains will turn out not to be, and buy it now sales that take offers may be at least as good as auctions. Unfortunately I think on eBay and elsewhere, most people selling instruments think they’ve got the next best thing to a Stradivarius and set their prices accordingly. Patience helps, and a willingness to bid and lose on ten auctions for every one won.