exactly my thoughts too. I was thinking the milestone payments are about a 10 - 15% of projected value. Roche certainly wouldn't offer a payment for less than it's worth, the idea is to help Inovio move forward but also would be crazy to pay more. They're trying to make a buck too afterall. But like most, that's just a WAG.
It has to work. If not, everyone loses. So far so good.