In the UK, an eyelash extension treatment can cost between £85 – £100, depending on your experience and where in the country your salon is based. The treatment will usually take you about 90 minutes. If your client wants to maintain them long term, they will probably need to come back every 2 – 3 weeks for a refill – the charge for this is usually between £30 – £50. However, when you are just starting out, you will need to be charging less for your lash extensions. While you are building up your client base and skills, you could run a half-price offer to get yourself going.