On a side note: when booking QKL to FRA LH charges €40.- for a 'fuel and security surcharge'... Still, the tickets from LH are quite a bit cheaper than if you buy at Deutsche Bahn directly (without reductions, that is).
Outch.... LG is quite a bit cheaper?
DB charges 118 Euro return, LH 123 Euro plus TSC for a flexible return. The inflexible return is at the time being 58 Euro on DB, 96 Euro plus TSC on LH