asOkay im not sure if you know but the basic course on Gelish Application is Approx £50.
I am not sure what others are charging but i charge £25 for gelish block color application ... £30 for french. If they have a glitter top coat on top of a block color, I charge £30. Ofcourse it's up to you. I believe in charging not only for my services but for quality products.
Gelish is worth it !
Don't be afraid to charge for a premium product! It's not a cheap system to buy in but it is very profitable and does exactly as it says it will ( if applied correctly and good aftercare)
I'm sure there will be other geeks that will share thier pricing with you