Hello woolly,
The prices can definitely be too much at times, which is why we have the cubit system. Cubits are another currency for the webstore. 1.0 Cubits = 1 USD.
There are actually some ranks for the different servers, such as /ranks in both Skyblock servers, the grading system on Creative (D, D+, C, C+, etc), the ranks on Olympus like Titan, I believe the command to see those is /rankups or /rankup .
There aren’t really any for Survival, I don’t see a use for them anyway as the main objective of survival is to… not die, and to make money, build whatever you want, etc. Same goes with KitPvP, not really a use.
There aren’t any /ranks for islands though :(
Let me know if I’ve missed any.
I have to agree with Sonic - Vip+ Is probably the rank that is most worth the money.