My neighbor once ordered 50m for over $130, when buying it here he could have easily gotten it for $45 or less.
If your mind is set on buying it somewhere else, try www.gold4rs.com. I've dealt with them before. They're fairly fast. They've recently gotten a huge increase in customers, so they're having to hire new tech support staff. Just buy the gold with your username and stay online. They'll message you with a world.
I have bought gold from www.rsorder.com , but it is a lot cheaper if you buy from someone one here. On rsorder I paid $28 for 10mil. Here i bought 40 mil for $34.