My view is that you should invest in a quality product, and here's why:
There's 2 sorts of clients. One sort wants cheap nails. They dont care that their cheap nails look just that - cheap, and they will never be loyal to a tech or seek out a tech with discernible skills. They will flit from tech to tech depending on where the "special offers" are, and you will never make a living by marketing yourself to this type of client.
The second sort of client wants decent nails. this sort of client wants people to stop her in the supermarket and say "wow, who does your nails?", and they will pay a premium for this service. When they find a tech who can deliver exactly what they ask for no matter how one-off or unusual the request may be they will stick with that tech. They will look after their nails and maintain them regularly with regular appointments. These are the clients to level your marketing at because these are the ones who you can profit from.
I know we're all in this industry for the love of it (I'm not being glib, I genuinely would continue to do this if I won the euro millions and have never met a tech who feels differently!), but until I come into the big bucks I need to pay my bills, so its just sensible to aim your business at the most profitable market.
However, having said all this it's rather a moot point and here's why. I read an article quite a while back (I cannot remember who wrote it or where I saw it so apologies for not referencing it), but the author had calculated the costings per service using the cheapest products available, and the most expensive which happens to be CND. The difference in price per service was 4p!!! So, if you really are watching the pennies (literally) then by all means use the cheapest products you can get, but you're only saving yourself 4 pence per set of nails by doing this. Offset this against the cost of lost business when your customers find other salons who can deliver a better quality service and nails that dont lift, and your cheap product isnt really that cheap.
It's a no-brainer really!!