I started about a year ago, and did it every day until about december, then that cut down to about 1x a week (if you averaged it out XD)
I'm at A35 atm I think, which is Journeyman status, pretty sure I'm close to A30, which'll let me chance digging up elemental ores (chance.. XD)
I've been making decent enough profit on it for a while, it just takes time moving around space and going for it, often forget, but if you do it everyday, even if you only make 20k, that helps pay for food, and your still skilling up, it adds together (I almost always break even, which is enough for me, but seem to average on ~30k profit a day, I've only lost gil like maybe half a dozen times since starting, so craftwise, while its lacking in skillups comparable to others, the input loss isn't really there... in begining you may loose out on gil, but you may not... try doing hot and cold as well, its free and in good skillup areas for starting diggers)