We could have custom tags other than the ranks. Then we could rankup with special kits, etc. What do you think? I've had this on a skyblock server and it worked well.
So, for example, you start out with no rank.
Then say, 30k to rank up to [Baron] then 100k to [Earl] then 200k to [Duke] etc.
It will be interesting because people can get titles without owning a residential town. Then, as a noble you can be special in some way.