Rework dynamic pricing system
-Track the number of items purchased in a given interval (IntervalHours convar, default 6)
-Track an average number items per interval for each sale
-At the end of an interval, update all prices. If the average has gone up in the prior interval increase the price by 5%, if it was lower or equal reduce the price by 5%
-Make the price start at 300%, so it will naturally tend down at first for a while before it normalises onto the price the market thinks it is worth
-Expose the MinimumPriceMultiplier, MaximumPriceMultiplier and StartingPriceMultiplier
This removes an array of objects per sale order and replaces it with 4 saved numbers, so this is a big simplification