If you spent bitcoin at $120 expect $120 worth back, key word here is spent. I'd love to sell a oz of gold for $1200 and go back next week when it's $1500 and ask for it back. Come on people you spent it you didn't hold it.
If I traded an ounce of gold to someone in exchange for a product or service that they subsequently can't provide, I'd expect to back an ounce of gold. Regardless of current value.
With that said, I've already stated I'm willing to forgo any assembly refund as long as I get my shipping refunded in the original amount of BTC. That seems really fair to me. But it's apparently not even worth a response from our esteemed group buy leader.