I'm not sure if you've already seen, but denise has answered this elsewhere - because of the way they calculate it, any smaller paid account option would cost exactly the same as the normal paid account, and therefore be pointless. They calculate on the basis that a certain percentage of users will only be using 30 icons out of 100 anyway. So if you want a smaller paid account option, you already have it - it's the normal paid account. Anything else would upset the business case and risk the whole site.