If you want to buy such a large amount i would recommend to NEVER trade that much in one go and especially not OSRS Gold. Do really good research into a seller that cares about RWT safety and bans. Make sure they use high combat level accounts with a decent total level, make sure they use P2P worlds. Also buy OSRS Items instead of OSRS Gold. If i were you i would buy a twisted bow + scythe for instance. This would look like some PVM member is loaning you the items (which is actually done often amongs players). Then 1-2 weeks later do another purchase of some other OSRS Items.