Without superheating gold, it's still a relatively cheap way to 99 smithing. Using the edgeville bank/smelting location I was able to get 72-99 smithing in about a month. I have not achieved 99 mining but LRC can provide the gold needed for 99 smithing, or you could afk mining at the dwarven lava flow mine. This is also where you get the mining boost outfit/gilded pickaxes if you didn't know.