Quote from phoenix_rising:
If you are undercapitalized to start, having a $7200/year automatic drain on your account because of the API sure isn't going to make things any easier.
That's if you don't trade at all. Otherwise the $600 are discounted at $50 per $1M of transactions which is rather easy to reach if you have a good system and enough capital with regards to trading frequency.
But I agree it's definitely not a good idea to subscribe outside of these conditions.