Currently member invoices have one fixed price, in our scenario the total sum due is made up from 5 components which can vary from year to year, to get the total price. i.e. gold member = $100 ( $30 sub, $40 levy, $5 levy, $5 levy, $20 levy ). levies are all mandatory.

Rather than use the work around of extra membership charges via membership fields, I feel this (1) should be included within the membership level editor? (2) I don't believe it is very robust and have concerns re retrospectively activating this and it not working?

The final invoice might look like;

Gold Member $30
Levy A $40
Levy B $5
Levy C $5
Levy D $20

Total: $100