so a delegate will need the support of at least three hundred voters to become a member of the magic 101 circle?
There's other considerations. Not all testnet users are equal, some are now whales. Several have hit the faucets repeatedly and accumulated a lot. Plus, the 101 have forged a lot and most now have 10,000 - 20,000 each. So you can become a testnet delegate if you get 15-20 out of the testnet 101 to sponsor you.