Was just wondering if it was decent money at all doing living rock creatures even without 77 mining?

No, not decent money, but the exp, in my opinion, is well worth it. If you can - use a cannon to speed it up, they're really massively long tasks.

Ok in another note approx how long would getting 20- 73 mining take?

Ok in another note approx how long would getting 20- 73 mining take?

 

That would depend on how much time per day you would wish to put on Mining. I recommend that you power mine iron in the Falador Dwarven Mines, next to where the resource dungeon is because if you can get inside that dungeon you can bank the iron and make some money. Whilst doing this, you may want to get a Gem Bag from Dungeoneering also, and wear a fully charged glory so that you get some gems, which again is a nice little profit maker. If you wish to mine Coal, same thing really but get a Coal Bag as well for more exp per invent, though I don't recommend coal because of the sheer amount of bots there is.

 

If you put about 3 hours per day on mining none-stop, you'd possibly have it in a week or so? I may be over-estimating.