I received an email yesterday that said : Save up to 50% on TSW content this weekend! When I clicked it on my phone I could see that the extra CSX engine download was half price. But now it's back to $19.99.
It's half off for me https://store.dovetailgames.com/us/product/463386/train-sim-world-csx-gp40-2-loco-add-on Remember, you have to get these sales off of DTG's store, not Steam.