It really is impossible to give an amount as there are so many variables. You need to make a list of everything you need such as the rent & attendent solicitor costs if a lease is involved, signage, printing, all fixtures/fittings, products, business rates, refuse collection (as it's not always part of business rates), public liability & contents insurances, electricity, water rates, telephone bill, card machine (if using one), licenses (if performing electrolysis, also data protection & to play music in the salon). When I did it I found it easier to list everything I needed, then everything I wanted if I could afford it, and ended up somewhere between the two.