My understanding is that she can spend up to half their joint assets, which means she can spent $25 million. She's already spent more than $11 million and they have $20 million in debt.
That's part of the equation for the Clintons.
That's a malleable part of the equation. Donations may slow down, but they won't stop. I have no idea when the primaries will be over. I can no longer even recall when they began.
Costs won't slow down either. If she has to campaign until the convention she will run out of money. I think that realization is what will finally get her to admit defeat.
I can't imagine costs will be anywhere near the same going forward. Aren't the biggest costs advertising, especially TV? Only cheap TV markets from here on out, and zero advertising costs after the last primary. She should also be able to cut her campaign staff way back after the primaries. If she wants to stay in, then I suspect she'll have the resources to stay in.
When you are millions of dollars in the red every additional cost is a problem. At some point Hillary has to pay her bills. If she can't do it now then she won't be able to do it a month from now because donations will dry up without any new races to energize her donors.
