Doing it the cheapest way you could get 99 without wasting all that money although it would take longer. On RSWiki, I saw that you could get around 1M xp/hr (I have no idea at what level/doing what/if SC hammers were included) without paying attention to cost that is.
Spend 30m and time for enough Sc hammer for 99.
Worked from level 50-99. Using Oak Larders to Oak doors.
Teaks and Magohany are very fast exp but the price are somewhat decent..
(That is if you bought the logs n made into planks or just bought the planks)
You can actually get 99 smithing. Do oak larders until you can do dungeon doors. If you also use sc hammers you can do the whole thing hand have 5-10m left over.
door it to 99 with sc hammers and you should be close...might need to spend a little more with current prices..
personally i hate sc, and do not enjoy the minigame so it would be horrible in my eyes and would rather spend the money cuz its easier to make money than play that game haha