Anyone know why? Some of the tiers more than doubled in price, that's pretty insane.

Hardware prices, especially RAM, have skyrocketed. Priced out new baremetal servers recently and prices were 3-6x what we paid 4 years ago for the newer equivalents.

RAM prices, surely?

Was looking into a ram upgrade and the kit is 4x what it was even a year ago. I'm with you on this one