Here's a chart of just about all prices in the area:
https://www.jungfrau.ch/fileadmin/Prospekte_und_Broschueren/Jungfraubahnen_Fahrpreise_Preisliste.pdf
So it's 23 CHF for cable car up to Mannlichen, you hike to Kleine Scheidegg, and it's 24 CHF for the train back to Wengen. If you walk further, "around the corner" to Wengernalp, you save 7 CHF because from there it is only 17 CHF back to Wengen. I don't walk further to save money, but because it's a great additional walk next to great mountain views.
Andy, I don't know if you've not been there and are trying to decide if it is worth it. If that's your consideration, I'll say this about buying those tickets: If it's a clear day, YOU WILL NOT REGRET IT--TRUST ME ON THIS! I consider this to be THE best trail in the world. If you want to see pics of this trail and the other great dozen trails in the area, send me a private mail by clicking on my name.
Yes, prices are expensive, but you can reduce those by buying passes like Berner Oberland Pass, Swiss Pass, or half price card.