Yes, the Lauterbrunnen Valley does indeed resemble Yosemite Valley. To continue the analogy, picture the car-free villages of Wengen and Mürren pierced above the Valley, 3000 feet higher. Mürren would be on the right as you face into the Valley from Tunnel View, roughly in the position of Glacier Point. Wengen would be on the opposite side, say near the top of Yosemite Falls.
If preparation for the TMB altitude is your goal, there is more benefit to staying at one of the higher villages, especially Mürren. We spent 6 nights there before our TMB in 2018. We have been there several times before, and prefer it over Wengen, Lauterbrunnen, etc. for the better views and more hiking right from your door.
For an inexpensive place to stay in Mürren, consider Chalet Fontana, a Bed and Breakfast run by a lovely British woman. The upstairs rooms ( a total of 5) have a shared bathroom, but if that is not your preference, the ground floor apartment has its own private bathroom. And you still get breakfast with the other guests. We have stayed in both types of accommodation there and found them perfectly acceptable.
With a more liberal budget, I would suggest Hotel Bellevue.
If you would like to choose Wengen instead, Hotel Bären is moderate in price and serves excellent, gourmet-quality dinners. Take half board there and you will enjoy nice meals, including, in addition to wonderful 3- or 4-course dinners, the best breakfast we have found in Switzerland.
