https://forums.backpack.tf/topic/6033-rules-for-unusual-price-suggestions/

so basically the next steps you should do is:

1. Find out how much Cool Secretly Serviced War Paint (Min Wear) go for

2. Price it here: https://backpack.tf/stats/Decorated%20Weapon/Secretly%20Serviced%20%7C%20War%20Paint%20%28Minimal%20Wear%29/Tradable/Craftable/703

2a. Here is the steam community market buy you'll need to find out which one is which to use here, which like good luck lol https://steamcommunity.com/market/listings/440/Unusual%20Secretly%20Serviced%20War%20Paint%20%28Minimal%20Wear%29

3. Use a single value here as a price (so if it were like 50-60, you use 55 as the value for this suggestion)

4. repost this suggestion with those things done

It's simple in process but difficult because you don't have any real data to go off of for the war paint. Unless you can find the history of the war paint before you made it into a shotgun, it may be difficult.

but Vrakos posted the rules link because you need to only have 1 value since there was 1 sale (no range), and then there is very little supporting evidence used here, notably you have not proven the price of the warpaint, just given a rough estimate and then added a range.