In it's current form, most skip the fun users are people who bought a second cd-key in order to use the skip the fun feature without losing their mains and since I doubt this was the intention when skip the fun was introduced I would like to suggest a new approach: allow one skip the fun alt for everybody, no matter how many chars they have but make it cost 100k gold to create. Every time you want to respec your skip the fun alt, you must delete the old one then pay another 100k to create a new char.
The gold is substracted from your main character. The 100k is just an idea, although I don't think it would be too expensive looking forward to the extra gold that will come from Strategus and a new cRPG gold sink might also decrease the inflation caused by the market.
In addition to this, keep skip the fun in it's current form - if you have no characters you can create a skip the fun char for free and use it as main in Strategus, so new players or people that only use the skip the fun character are not affected, but forbid usage of multiple cd-keys.