What Next

I see three things that could use a bit of upgrades imo.

1) Your work glove, upgrade to a 12 attack? Dunno the prices now, but they were pretty cheap when I stopped playing.
2) Scrolls your Z-helm with 60%s. 100%s are cheaper yes, but later on you won't have to upgrade again if you have a decent helm now.
3) Upgrade your cape, 3 attack 6 dex can be upgraded to a 3 attack 10 dex with no problems.

I agree with point 1. However, points 2 and 3 are disagreeable.

1) He has 158 Dex and he is aiming for 160, why bother wasting valuable money getting more Dex than you need?
2) If you remove his cape, he'd need 8 more Dex. So why not try to pass a 60% Dex scroll on the first slot of a zhelm and then simply 100% it? Or you could try completely 60%'ing it. This way, he'll also be able to get himself a Luk cape.

Either would be far more efficient with mesos than what you suggest to do.