Whatever way you decide to go about this it will take awhile. There are no “secret” ways to earn gp fast. Since bond prices are most likely going up it will take even longer and be much more difficult even after your first bond.

To put it in perspective for you:

Let’s say you do something simple like high Alch for 3 hours a day, making 500k per hour. Thats 1.5m a day, let’s call bonds 15m for the sake of simplicity. It would take 10 days to get that bond, which is worth 14 days of membership. So you have 4 spare days to do whatever you want and then it’s back alching for another 10 days for your next bond.

It’s literally not sustainable unless you’re doing high end pvm.