If applied properly then there is absolutely no reason why lashes can't be worn indefinitely. If lashes look like they need to come off after 6 weeks with regular infills then you need to change your lasher!
I have clients that have worn them for months and months and there is no damage to the natural lashes and they still look good after regular infills.
Obviously you need to apply the right length/weight lashes to your clients. I have had clients that want really long and thick lashes and if their natural lashes won't support the weight then I won't do them. I explain to clients what thickness they can have and that you can make them look fuller by applying shorter lashes inbetween. I only apply lashes that their natural lashes can support as I care about their natural lashes. Maybe you are applying the wrong length and thickness if your lashes are looking like they need to removed so quickly. Can I ask who you trained with?
In answer to the OP, I charge £50 for a natural set (40-50 lashes per eye)
£75 for a full set (70-80 lashes per eye)
£100 for a glamour set (100+ lashes per eye).
