Yes, waiters at high end restaurants do, in general make more on average than waiters at lower end restaurants. Many high end restaurants do keep their staff on similar pay scales or grades as lower end ones however, do keep in mind that even part time staff at these places tend to have to put more hours in per day. In addition, most diners at either end of the spectrum tip on a percentage basis; considering the price differential at 5 star restaurants, you can imagine how much larger the tips would have to be.
Often the initial cost of working for higher end restaurants is greater though. Many of these restaurants require that all staff be educated in hospitality and service, often requiring a college degree at the very least. In addition, staff are often required to take courses on a regular basis to keep them updated on service trends and etiquette. For example, waiters at higher-end restaurants need to be well educated in dining etiquette (serve the ladies first at the table; serve entrees from the left, collect from the right; serve beverages from the right). Wait staff are also expected to be able to make wine recommendations for each course (which often requires a wine tasting course depending on the restaurant and management). Additionally, wait staff are expected to memorize the daily specials and be able to answer questions about any dish on the menu. Often, to make this happen, wait staff are expected to arrive for work two to three hours prior to their service so they can try each course and gain insight from the chef and Maitre D'hotel. These are just a few examples. In certain situations, wait staff are also required to be more involved in food preparation, which, as you can imagine, requires a fair bit of in house training.
So, in short: yes, wait staff at higher end restaurants do, on average make more than those at regular restaurants. However, the jobs themselves are quite different, with the former being significantly more involved. This is not to say that wait staff at regular restaurants don't work hard, by any means, but the tasks are quite different for both and they are far from being the same job. It's like comparing apples to oranges.