I am looking at buying 300K miles speculatively using LH's package sale. However, one thing I'm curious about is truly how much the fuel surcharges are like on tickets (and also how the availability is on flights). I'll give one example:

I saw I can get 55K roundtrip J from CLT-MUC (on seemingly their new J class A350). at 1.18cpm that comes out to $649 RT for J. Now given the extremely low effective base fare, I'm fairly tolerant to hefty fuel surcharges, but how hefty are we talking? Even at $1000 roundtrip, $1650 RT for NA-EU J sounds still pretty great to me. I tried doing a dummy search, but it seems like I need 7K miles minimum to search so I have no idea of how widespread availability is or what the actual surcharges are like. Could someone educate me?