Hahn is well into the three digits. Avoid.
Keep in mind that Mannheim is heavily restricted for IFR landings, and for MEP landings in general. You can’t legally land there unless you have fulfilled certain conditions. See AIP.
The general Frankfurt area is terrible for IFR flyers. There is not a single pleasant IFR airport within many miles.
Saarbrücken might be OK for your purposes.
If you want to refuel in the aera maybe go to Giebelstad EDQG, just make sure they are open. They have rather cheap JetA1 (currently 2,25 EUR / liter with all taxes private which is well below other places) low fees and IFR procedures without much traffic.
Thanks. I’m pretty sure I’ll land to Liege EBLG – EDFH and EDFM are alternates, although there are few other airports in Belgium and France which I can use in case something goes wrong at EBLG.
If you’re ok with VFR-only then I’d recommend EBZW or even EBST iso EBLG. Much cheaper !
