I was trying to think of a way for shops to be more dynamic, since the only thing that really changes about them is the number of guns in stock (and even then, it's pretty stagnant). So, this is what I came up with:
*If you don't want to read the whole thing, basically I just explain how a system to change the shop prices daily would work.
(and there's a spreadsheet at the bottom to look at.)
Shop prices vary +-1-5% (plus or minus one to five percent) every day at 12 servertime.
50% chance for +1-5%; 50% chance for -1-5%
Every time a gun is bought from the shop, +1% chance for +
Every time a gun is sold back, +1% chance for -
(As an example, Someone buys an FN2k from Fort Knox; there is now a 49% chance for +1-5%, and 51% chance for -1-5%)
Each time a gun is sold back to the shop, 1 of that type of gun is restocked.
(this doesn't have MUCH of an effect on the price, but It never made sense to me that those guns should disappear.)
Sellback value is equal to 75% of the current shop price
(as it is now, sellback values range from single-digit percents to in the 80% range)
The STARTING percent chances would be as follows, but would change over time:
30% chance for +-1%
25% chance for +-2%
20% chance for +-3%
15% chance for +-4%
10% chance for +-5%
Each time a +-x% is chosen, -1% chance for the +-x% and +0.25% chance for the other 4 x%s.
(As an example, let's say +-1% is chosen 3 times in a row. it would then have a 27% chance of being chosen, whereas +-2% would have a 25.75% chance, +-3% would have a 20.75% chance, +-4% would have a 15.75% chance, and +-5% would have a 10.75% chance; all still adding up to 100%)
This has a balancing effect in the long run, but in the first few weeks, 1% should remain dominant, leaving the prices to remain generally the same on a day-to-day basis, and leaves room for the market effects to kick in later.
I made a spreadsheet to illustrate this system which shows how a 100k gun would change prices each day for a month. The price ranges from 107% of the original price to 95% of the original price, but if that degree of variation is too little or too great, the numbers can easily be changed to increase or decrease the effect.
The link to the Spreadsheet on Google Docs:
https://docs.google.com/spreadsheet/...mRUVlpqVkk4dlE