I would also like to vote for this option.
Our association currently has three membership levels:
Individual Membership
Student Membership (reduced rate of individual membership)
Organization Membership (allows for up to 3 individuals to have one shared corporate membership)
For new members applying for the first time, we have a setup fee which is added to the first year of payment. We require our process to allow for this setup fee one time, then renew at the normal rate.
I don't currently see adding a one time additional fee to new members for each level. We do need to do this! So any advances toward this area would be much appreciated :)