upgrade

Is there a way to set up an upgrade option. we have classic and gold members, some functions are gold members only but if a classic member wants access they will need to upgrade by paying extra, is this going to be easy.

J

I have something similar based on these 5 plans:

Code:

1 week   = $20
1 month  = $30
3 months = $40
6 months = $50
1 year   = $60

I want to allow people to upgrade from one plan to another by paying the difference in price. Do I need to create:

4 upgrade products for people who want to upgrade from 1 week
3 upgrade products for people who want to upgrade from 1 month
2 upgrade products for people who want to upgrade from 3 months
1 upgrade product for people who want to upgrade from 6 months

ie. Do I have to make 4+3+2+1 = 10 new upgrade products, or is there an easier way to do this, where people can credit the cost of one plan towards the next?

Regards,
Ian Tresman