Maths behind sliding scale pricing
I'm trying to work out a simple calculation for the following:

a phone model has the maximum sale price of £85.00 and this is if only 1 unit is purchased and a minimum sales price of £50.00 - this is if 150 units and over are purchased in one.

How can I work out a way of the price if between 2 and 149 units are purchased??

Thanks,
B.
Maths behind sliding scale pricing
===

I'm trying to work out a simple calculation for the following:

a phone model has the maximum sale price of £85.00 and this is if only 1 unit is purchased and a minimum sales price of £50.00 - this is if 150 units and over are purchased in one.

How can I work out a way of the price if between 2 and 149 units are purchased??

Thanks,
B.