How much would I have to earn on steemit to get by in the UK?

Wouldn't it be great to make a living just from blogging here in the UK?

Now roughly how much would you have to earn a week to do that and still not have to cash out steem power?
Now if Labour win the election they want to set the minimum wage, or living wage as the conservatives (wrongly) rebranded it to £10 an hour, so on a 40 hour week thats £400 a week to get by.
Now this is simple maths work and guesstimations but here goes:
A $7 payout got me 3SBD, ( I don't want to touch steem power as that's my investment in steemit.) so a $70 payout gets me 30SBD.
Now I have to take into account converting my $ to British £ so earning $400 SBD will leave me short so really I need to be bringing in a minimum of $510 SBD a week and that would be, based on 3SBD from a $7 payout, $1140.
Once the SBD are converted into UK£ that would give me around £390 a week. This doesn't include any fees and things for converting my SBD into UK£.
So my guesstimate on earning a living blogging and keeping building up my account with steempower is:
I need a weekly payout target of $1400 working on a $7 payout to give me 3SBD.
$200 a day posting 7 days a week doesn't sound that bad and if we keep seeing things going in the present direction then it could become a reality.

Thanks for reading and if my maths is off please put me right.