I'm guessing by your comments Tom you want to know if you can possibly give up your job and do it?
Answer is yes imo you can. If you put in a lot of volume and by volume I'm talking 1000 tournaments a week which is easily possible if you grind out say roughly 150 a day and hit 10% ROI consistently then yeah. Even then though you would only be earning $3000 per month. With bonuses etc that could hit maybe $4000 a month, which is like what £2,500 which is enough to live of per month depending on your expenses in the UK.
Of course that is maintaining a %10 ROI and my bonus estimates might be off.
If you put in even more volvume which could lead to bad results you could play maybe 200-300 per day, roughly 9000 a month but thats sick amount.
I know a grinder who plays lower limits and it is the MTT SnG's and turns over a very nice profit. He plays around 3000-3800 per month $2.10 180 man's and $3.30 Rebuy 180's exclusively and is turning over currently around $10,000 in profit monthly not including bonuses so of course it's possible it's just weather you have the skills to do it and grinding mind to do it everyday of the year.
Last three months he's made around $45,000 just by playing these at high volume which is indeed a very good wage if he can keep it up on a monthly basis. Probarly would be nearing £100,000 a year, a doctors wage playing micro buy-in stakes, how sick is that?lol