[robfitz]

Assuming the other terms of the deal are fine, you should accept both offers.

More money will always help. Revenue will appear and grow more slowly than you hope.

There's no reasonable way to calculate expenses because to do so, you need to accurately predict how your team & business will develop for the next 18 months, which can't really be done.

Just take whatever you can get on reasonable terms and move on with building the company.