USPS shipping pricing can definately be confusing. I do remember something about them getting rid of parcel select or post or whatever and if it was a certain weight you can only do priority
It's still there, thank God. My work uses it to ship packages to USA commonwealth states and remote places like Alaska or Hawaii. I imagine USPS would get a lot of pissed off emails and phone calls if they killed Post.
USPS prices always seem to fluctuate, especially during the holidays, but who knows. I remember last year a small FR box was down to 4.25 if you bought it through ebay or Ship Now, but if it is that much of a difference I may have to consider USPS next time I send something out.