Have two tiers of subscribers..
1/ gold members £2 month or £20 a year
2/ platinum members £3 month or £30 a year
Gives a choice and for the extra on the platinum tip could be aimed more at the dj's for extra data storage (1gig instead of 500mb)
You could also have a silver members bit too where they don't get the 500meg webspace, but only pay £10 as a one off for the year and still have access to mixes to download etc.
It's all about options, cadburys options mmmmmm
