He'll give that $100M, the RNC only has around $30M on hand, they need to raise $1B for the general election. Trump had literally 0 infrastructure 2 weeks ago, and they pissed the grassroots off again, so they are way behind in volunteer support. The Democrats are already built out, they will get every single voter out to the polls in November.
Trump is trying to sell people on the myth that he's bringing in all these new people to the GOP, voter data shows this is not the case, because the people who were poling as "new voters" were actually registered GOP who didn't vote last cycle.
What advantages do you believe Trump has? The same primary polls a lot of us ignored showing Trump with a massive lead are now showing him getting crushed by Clinton in almost every demographic except old white people. Clinton was going to be a tough sell, because she's not a good candidate, and not popular at all. The GOP have somehow managed to nominate the only opponent who is even less popular, in fact he's the most unpopular ever (with the exception to David Duke, who is not shown here):