[ohkanada]

I am not saying I would raise to 400 everytime, but getting headsup with a desperate stack is very attractive even with 55. Plus his stack is above average so I think taking a slight risk of a limp-reraise is worth it. Most players who limp for 50, would muck for 400, so the point of the raise is to get headsup. If you feel someone is trapping I agree just calling is correct.

You also missed the typical scenario of raising to 400, getting headsup and winning when your opponent misses (overcards or smaller pair) and you miss as well.

I think this option or your option 2 will happen 80%+ of the time.

Ken Poklitar