How to get into Lego trains without breaking the bank

My kids (7 and 9) have been asking for Lego trains for years. They already have other train sets (wooden set, duplo) but nothing with motors. They do have so many wooden tracks and bridges that they build some crazy layouts all over the living room and have played the hell out of them for years. I have always found the Lego trains to be so expensive, like the 60337 set (Passenger train) running at 160 euros. Now they want to spend their savings on that one, and I just feel like for that...