When you say that you "are willing to ___", it means that you will say "yes" to doing it, but you don't really want to do it, or you're not happy about doing it.

For example, if your lazy grown-up child asks you for money, you can say:

I'm willing to lend you the money, but I expect to be paid back by the end of this year.

Or if someone offers to buy something from you, and the price they offer is lower than you want but OK, you can say this:

Yeah, I guess I'm willing to sell it for that.