Go to a PVP world, the autoer will have 25003 gp in his inventory and your main 75003 gp, (or just 26k and 76k), then, you just kill the autoer on your main and take loot and go to safe zone. Repeat. If you have such a big level gap that you can't fight in PVP, go to Wilderness to some quiet spot, e.g the walk up the west (as west as possible) side of wilderness, the western side of the west green drags, until you are able to attack your autoer, then just bank every 300k or so, so if you get PKed you don't lose much.
This way you will get atleast 100% of the money transfered
