I explained above why a loss (or gain) in bitcoin relative to the locked currency does not imply a loss on the books for the service. (It's not complicated.) For some reason you're still pretending that a 79% loss in the price of bitcoin relative to the USD implies the service provider has a 79% loss on the books. Now the question is: what is your motive in pretending that?
Maybe I'm wrong about it not being complicated. Buying and selling BTC to account for locks without speculating on the price seems obvious to me.
Maybe the obvious way most people would implement locks is something like: "I got a great idea! I'll take someone's bitcoin and give them an IOU for $250 worth of bitcoin. Then I'll hope the price goes up so I can pay them back and make a profit!"
The second way sounds, well, I'm tempted to say retarded, but that's just too insulting to retarded people. I seriously think most retarded people could see the second way is a bad business plan.