Hello, I'm from germany and im quite familliar with the Märklin Sets and Locos. I cant tell you how much your Set is worth since it heavly depends on its condition and if it works or not but if the Set is complete (full loop of track, all rollingstock included) its a nice novelty to have. As for the blue switch panel, the buttons being loose and weird to press is normal. Its just a squishy button but it does its job. Getting a transformer for this shouldnt be a problem since Märklin themselves advertise it on their site https://www.maerklin.de/en/products/deta...ticle/6646
If you have any other questions feel free to ask
Cheers
If you have any other questions feel free to ask
Cheers