Do a phone round all your salons and mobiles locally as if you were a new client sussing out their prices.
If you are confident with the work you do, I would say charge at least the same as the higher priced ones.
You are a mobile salon offering a professional service; why should this be cheaper to them? The benefits to them are:
They can stay in the comfort of their own home, in the warm
They don't have to find a parking space
They won't smudge their polish on the drive home
They can keep an eye on dog/granny/child/have a parcel delivered etc
You probably offer more flexible appointment times than a salon
They don't have to sit and wait for you to finish the previous client
They don't have to queue to pay or to make their next booking
Jeepers, with all that on offer, don't underprice yourself!!!
I'm speaking from experience when I say, it is a lot easier to start with higher prices and make special offers to begin with if you feel you need to, than it is to start low and raise your prices considerably when you realise you have pitched them too low.
With regards to increases, I find that raising prices by 50p or £1 more often is accepted whilst waiting 2 years then sticking the prices up by £2 or £3 is not.
Good luck :hug: and remember you ARE a salon - just a mobile one!! If you wear a tunic and carry professional equipment it will all help you look and feel the part.