I need some advise=)

I have just completed Megabonus promotion, and got an email 'reminding' me about the existence of Megamiles.

I have 3 more stays/nights coming up, each of them cost about 80 euro per night. Made some calculation and wonder it will be a wise move to switch to Megamiles. Made some calculation, which doesn't help me to decide in the end.

Usually I choose the points as welcome bonus (my girlfriend hates wine and cheese), so I will be literally losing the welcome bonus if I switch to miles earning.

Target airline program will be Singapore airline/Lufthansa airline. I'm not loyal to specific airline though. Holding about 7000miles with each airline program.

Thanks a lot.