I agree with the above. My guess would be the T stat is bad. As for that quote, radiators run $300ish from NAPA, I haven't run a quote on a water pump but I wouldn't expect much over $100 and a T-stat is around $10. Add $50 for coolant and they are just doubling the cost for their labor, that whole job would take 2 hours tops and at $90 an hour they are still a rip off.

The other thing, and the lack of pressure would not be because of this, the radiator fins could be plugged up. Look and see if there is a lot of dirt, grass or bugs in the fins blocking air flow.

I know a few years ago a new radiator cap from Ford ran around $20 FWIW. Also did you try and squeeze the upper radiator hose after this drive? It should be too hot to touch with bare hands and have plenty of pressure in it.