2k for 20 days... 100tc a day... 10 wins in a meh-payout official server a day would cover it.
It's pretty reasonable, and easily done with next to no real effort unless you're incredibly bad at the game.

Creati0n says: Currently the Wibbles subscription costs 2000tc for 10 days, so all you have to do is win 20 games in a default public server. If you play in a blackbelt room, it's only 8 wins a day. It isn't too bad.