one step at a time.
I'd first stop giving away free Steem on registering, most of which goes to bots anyway.
then use the giveaway money to buy steemdollars (which backs steem) or to lock it in a develoment fund or even better reduce the inflation which in the first year seems way too high (200%!).
paying to register seems a step too far right now, a user signup slump would be risky, and the current low payouts are not inviting enough for people to actually "pay to play".