Let us start with OSRS gold GWD. Yes, 90+ in all skills is more then enough to get a good team and do good. You truly won't need 90+ prayer, however, unless you truly want it. 70+ will be just fine. By coaching with slayer, you're going to get about precisely the same amount of expertise in charms because you can slayer experience. By way of example, 20k slayer experience should get you about 20k experience worth of charms for summoning, but it varies a little bit throughout tasks.

80 mil is more then enough to get started with slayer. I suggest you do Smoking Kills pursuit first in the event that you have not. Buy a black mask, and save rewards until you are able to turn that mask to some slayer helmet. You might also get a dragon plate and legs and spend the remainder on a sgs if you would rather have an sgs. At greater slayer levels, slayer can indeed pay off prayer. The occasional slayer item drop will pay of items. When you get to 83 slayer, then you can possibly acquire several monster boot drops in a single trip.

You can train range in tzhaar possibly because you want more income for prayer. You are going to be collecting onyx bolt tips and possibly tzhaar armour and weapons. It won't be a massive profit, but might help you out some. You could also try out ranging a few tasks, such as fire giants if you get those. That is all that buy RS gold I can reply for now, fantastic luck though.