Thought I would reply as lots have read and run...! Its a bit of all of them really..
You will get the clients that want to know what solution you use, looking for a famous name, but if you are confident with the tan you use, then you could perhaps on starting back up, offer it at a small discount to get them to try it ..tan for a tenner etc.? I use Nouvatan which I settled on after training with Fake Bake and trialling several solutions.
Regarding price, the litre bottles can vary between brands, but going for the cheapest/most expensive may not be any indication as to whether YOU will like the solution to work with. Over the amount of tans per bottle, the difference works out at a very small amount per tan. Also, some spray 'thicker' than others and will use slightly more per tan. The best thing to do is get some samples and some models and try it for yourself.
Clients (in my opinion) tend to fall into 2 categories..those that will only have a 'named' brand, and those that don't care what it is as long as it looks good! When I started, none of my clients had heard of Nouvatan..now I get clients that google it and find me locally!! If they phone and ask what tan you use/ do you do xxxx?, if you don't then say that you ' believe your tan is better because ...etc.., come and try it at xx discount' and you may have a converted client for life! Good luck xx