data analyst? Well that explains it!
Remember you're competing with local DJ's wherever the booking is!
Just showed it to my partner and her friend and they thought it was confusing as well, especially with the early set-up, background (then deducting the early set-up), mic and pa options (then deducting the early set-up) to factor in - Linda's words were, 'I wouldn't have a clue how much it was going to cost me!'
And I still don't know what the fixed charge is and why it changes depending on area if mileage is included in the hourly rate.
Looking at it from your clients point of view, they really don't care how far you have to travel - but you're planting the idea that booking a DJ nearer to where they live can save them money - that can't be a good thing.
(Imagine you were looking for a plumber, electrician, builder etc and one charged extra per hour because you were further away - wouldn't your first thought to be to look for a closer one?)
Charging by the hour will also get you people trying to book you for the minimum number of hours possible, that's human nature. Once you've said you're free on their date and they come back with we only need you from 9 - 12 there's not much you can do about it (apart from refuse the booking because it's not long enough).
And potentially, early set-up at £35 (no background or mic wanted), then book you to play from 9-12, that's a lot of hassle for not a lot of money. (£235 if they were in band 1). How would you handle an enquiry like that?
Once you're at the venue I think the price should be the same for everyone (and that you're happy with as well) - so the only variable is the travel. Use whatever catchment area you're happy with and add a mileage charge beyond that. That has to make more sense than charging different people different hourly rates and then letting them see the pricing differences on your site.