Heads up to those who played CS:GO years ago and like money. I was a pretty active player from 2012 to 2014. Back then I got dozens of crates that I didn't open, now worth as high as 31$CAD each. I looked it up last week and it's worth over a thousand dollars in Steam. I cashed in on almost half of it and now I have some cash to buy games for my family and friends.
There are plenty of sites out there that can give you a value of your inventory. Just make sure your privacy settings for your inventory are set to "public": https://steamcommunity.com/my/edit/settings (though I'd recommend changing it back to private after you use one of the tools, since scammers will try and target you if you have public high value items).