Then you get into the question of what qualifies as a party for purposes of getting public money. I can see this degenerating into a system for keeping non-established parties out.

I think our German system works quite well in that regard. The main reason the pirate party didn't join the Bundestag is they were largely incompetent. Infighting weakened them. Snowden gave them the perfect topic but all they did do is being reactive and saying the establishment is bad instead of developing policy ideas with they could have pushed into reality.

The main problem with establishing a new party is getting competent people together who are willing to think deeply about public policy and who don't destroy each other through infighting.