You can't sell them for maximum in the Grand Exchange. Jagex looks for the best deal if any offers exist.
If you put in a GE order to buy for maximum, you'll automatically get paired to one of MANY people selling them for minimum, not to your other account selling them for maximum.
You could buy them for min and sell them directly to the transferer for market, but you'd only make 5% on what you buy, and the transferer would be stuck with the Willow(u). You'd lose 95% of the money until the transferer unloaded the goods by junk trade or a lot of patience on the GE.
The person getting transfered to could MAKE the willow(u) and then sell them to the one transfering the gold, but that's a long process.
The other option is to find something that isn't offered at all on the Grand Exchangel, then work that for minimum/maximum. Good luck with that, since there's a four hour rule on flipping, and trying it with sets by buying pieces for min and selling the sets for max doesn't work, because people are beating sets to death.