A CS2 case simulator with the real odds and none of the cost. Open as many as you want, watch the counter tally what you'd have spent, and see how the actual thing works before you put money into it.
You lose money on cases over time. Valve writes the odds, sells the keys, and runs the market it all sells back on. The average unbox is worth less than the $2.49 key you paid, and that gap is their profit.
These come from Valve's own 2017 disclosure and haven't changed since. About four in five opens give you the cheapest tier in the case, usually worth a few cents.