This situation is different from a player betting $100 blind, because a blind bet is backed by a hand has equity in the pot. A dead $100 is just free equity to be split up between whoever contests the pot.
Here is a similar situation that I analyzed:
The biggest difference is that you have $300 in your stack vs. the dead $100. That means that you need to be more careful in what hand you choose to play. I'd be especially aware of what size stacks are involved or yet to be involved. Also, what type of range people will play in your situation will be dependent on your particular game. I know this doesn't tell you at all what to do, but if you like to tinker with pokerstove, you might gain some useful insights on what hands are profitable in this situation.