Sure, going to the top of the Zugspitz would be awesome, but so would not having to spend 50 euros to do it and then coming right back down!
Going up to the Alpspitz is a far better deal, in my opinion. For half the price (25 euros) you get to take several cable cars, see beautiful scenery from the top of the world and hike as little or as much as you'd like on the way back down!
There's a large restaurant at the top of the Alpspitzbahn, and although it's just traditional German fare it's well prepared and surprisingly affordable. There's another restaurant at the base of the Hochalmbahn, but the view at the top is where it's at.
There's a couple of "over the edge" platforms at the top to give you vertigo, as well as a series of hikes both around the peak and down all the way to the Kreuzeckbahn. We hiked a few (with snow!) and ended up with a fantastic view of the Zugspitz peak!
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.