Aye, there's many a bargain been had as an aged tup.
I bought a retiring 'stock tup' from the bloke I got my Blue-faced Leicesters from; only £100 (along with a couple of full-priced young tups) as he was thought to be likely to only make one more season. He did two, and threw some of the best mule ewe lambs we bred.
When we decided to try Charollais on our Texels here, we got an aged tup who would be serving his daughters if he stayed with the man who bred him. He'd paid over £3,000 for him as a shearling, we got him for £450 and he did two years for us.
And 'twas my neighbour's aged Swaley tup near broke my leg... but that was my own stupid fault, and that tup sired some super ewe lambs.