Juicy lucy, the only point I'd take up with your workings out are that brand A, presuming Shellac, is not sold in 15ml bottles, they might look like it but are in fact 7.3ml, just over a teaspoon.
I've checked on Bluesky and they are 10ml. Gellux is 15ml, etc
So for anyone working out, just saying.
I use OPI nail varnish which used to be pro only but is now readily available in some Boots etc and can be bought at Sally's by anyone. Doesn't make me unprofessional for using it.
I think we all know Bluesky started by being a copy cat product, if they now have MSDS that's a good thing. For people such as the OP in an area where people don't want to pay, esp if ALL salons etc are undercharging, I can see how it would make sense to use the Bluesky line as its a heck of a lot less outlay with. all those colours to buy.
And for anyone who didn't know, this site, being owned and run by CND, has more than its fair share of CND fans as you'd expect and anyone "going against the grain" is likely to get an earful.
Another thought, does your insurance cover you using Bluesky? X