So my hopes and dreams were crushed yesterday

I stopped at Ford on the way home from work to see when I can turn my 2011 Fiesta in (lease ends in June) to get an ST. He said I can trade it in now without having to pay the 5,000 miles I'm already over. So we go to talk about what the pricing would be. I told him exactly what I wanted, and he told me since my car is negative equity (no idea what that means) the better option would be to buy an ST. So he gives me a price of $370 a month. I'm like whoa that is amazing. I was expecting it to be like $600. He walks away and comes back and all of a sudden it goes from $370 to buy to $490 to lease for 72 months. I can barely afford that price, I'd be broke (with stupid school loans, otherwise I'd be able to do it) and there is no way I'm being in a lease for 6 years. So I don't know what to do now