Add option to set custom prices easier for quantity

[Valentina R]

When having custom prices for multiple people, the current system can be too confusing and time consuming to set up.

Instead of having to divide the numbers by the quantity number and ending up with prices with 10 decimal places, it would be much easier to have an extra field where one could set the actual price.

Example for 100$ for 3 persons:

• the ‘base cost’ and ‘slot cost’ expect 33,333333 to be set so that when there are 3 persons, the total amount is 100$.
• there could be ‘total cost’ option where one would put 1000$ and there would not be any multiplication. This is the actual price that would be disaplyed when Quantity 3 would be chosen.

Requested here.