Just getting my head around this.
So they currently sell their finished juice as either 50/50 or 70/30 at £5 per 10ml
Now they're selling these flavour shots for DIYers to make up at either 50/50 or 70/30 at £10 per 30ml ... plus the DIYers' costs for nic and diluent (approx. 10p) to make up 60ml of finished juice.
Assuming their 30ml flavour shot is 50/50, the DIYer would add 2.5mls of 72mg/ml nic and 27.5mls of VG to make 60mls of a 70/30 3mg juice, for approx. £1.68 per 10mls. In comparison with their juice costs, that's a pretty good saving - 66% discount for no real effort!
In comparison with other manufacturers' "one shot" pricing models, it's more than twice the cost. (e.g. £10 for 30mls of concentrate to be mixed at 15-20%. At 20%, you can make 150mls of juice for approx. £0.73 per 10mls.)
Mrs Lord are entitled to set their own pricing, consumers can choose either to pay it or not. Same old story.