I'd say it's rather something like this:
- Mighteers+1 (=Demol+12): 10-12m
- Strentes+1 (=Vigor+9): ~10m
- Snowboarder Suit (female): 80-90m
- Ancient Shield: 7-14m
- Guardian Knuckle: Not sure, I think 60m+
- Bunny Ears (male): no idea
Those are prices I see in shops at Darkon 2. I don't know if people are willing to buy them for these prices, though.