Pricing outline

I usually check trading sites (steamgifts, tf2outpost, csgolounge, etc.) and key sites like G2A, but the most important thing is that I adjust the price in order to get at least a nice profit of 1-2 euros (sometimes, I'm even getting a small profit like 0,5 euros).

Go to barter and see the [Tradables] and [Wishlisted] and compare, if a game is worth 20$ and has 200[T] and 10[W] and another is 5$ 10[T] and 200[W], the 5$ one is worth a lot more in the moment, obviously things chance ( if the 5$ gets bundled and the 20$ doesn't get bundled for some time the numbers beggin to move as supply decreases and demand increases )
The thing is if a 20$ game is so much common(lot of tradables) and have so few people that wanted(wishlisted) nobody will trade the game for 20$, if nobody wants it or few people want it its gonna decrease massively in value.
That and G2A/Kinguin but the price changes due to bundles/sales too.
My "rule" is if a game is unbundled i would trade it ASAP, if a game is bundled or trade in the first hours that it gets or wait some time after the bundle ends and pray to the gods it doesn't get bundled again sometime soon.