Ask HN: My lawyer has asked for 5% equity. Is that fair? 11 years ago
It's quite common for a banker to have a % success fee tied to raising a round of funding. Retainers are also quite common during these proceedings. You have to way the options of taking him on as a shareholder vs. paying him an up front % for the success of raising a round with his help (if he's involved with this).
5% equity does sound like a lot, but then again it might be cheaper in the long run if you get a solid contract stipulating exactly what services (hours per month/for how long..) this will include. Beware of the 'I'll help you out every now and then" type of agreements.