First of all you only need 69 for gilded altar (if you use teak selves 2 and crystal saw) and you get around 50k xp from each hammer. To find out how much money you need use tip.it skill calculator and the ge to find out (remember to divide number of planks needed by 2). edit: Screw it to get to 69 it will cost you 1,477,062gp and you will need around 7-8 hammers. Also oak larders are the best until 74 when you get oak doors. edit2: Been an idiot you will need 8 hammers.