US cities pay too much for buses

"Federal funding typically covers 80% of bus purchases, with agencies responsible for the remainder."

Well, there is your answer. The one making the purchase isn't the one primarily paying for the purchase. This makes them less sensitive to pricing.

Kinda like how expensive healthcare is since it is paid for by insurance.

Or how you don't care how much you put on your plate or what you choose to eat at an all you can eat buffet.

The second you detach the consumer from the price of something, even through an intermediary such as health insurance, that is when they stop caring about how much something costs, and so the price jumps.

It's even worse, I will use my healthcare just because it is free. I would feel like a moron not get my free physical, bloodwork and other labs every year. If it was $20 I wouldn't bother but its almost obligatory to take something "because its free".

Once I learn something is free it is like I already own it, so now I don't get it if I take it, I lose it if I don't.

Preventative care is free because it saves a tremendous amount of money for the insurance company and physical and emotional hardship for yourself by catching bad things early.

Your view is a commonly-held one, and makes a lot of sense; unfortunately there is very little support for it. One data point to the contrary is the Oregon Health Care Study, which showed that 'free' preventative care increased healthcare spending, but did not improve lifespan or reduce long-term cost.