Unless you want to spend 4 months buying rune med helms for the right price you might want to look into farming gold and using that to purchase bows you can alch with.. It's not that bad, I think you spend roughly 3 gp per experience, which when you think about it is really good.
If you're going for 99 and still want to make a profit; Mage metal dragons or do MTA. MTA is guaranteed profit but can be tedious as hell, dragons can be very profitable but can also turn into a huge "waste" of cash if you're unlucky.