A tad high, but if one goes up the chain beyond the store level, the rate of compensation climbs rapidly and often for work that any college graduate could do.One of my MBA profs addressed this issue...
Basically, you can't pay someone enough money to work himself to death...but if you pay the guy above him an astronomical sum, he (and all the other people at his level) will work incredibly hard to get to that level.
i.e. If you paid 20 Sr. Managers $500K per year, they would kick back at the Country Club sipping brandy. But if you pay them $150K per year and their Boss earns $5 Million, they will work long, long, long, hard, competitive, thoroughly exhausting hours to try to earn his job.
You are assuming that the managers are working themselves to death or that such demons won't go to work for some company where there are fewer layers between them and the top jobs. The major oil companies, for instance, have always had too many layers for the lower ranking mangers to aspire to more than just the equivalent of $500,000 level that you propose. This was true 70 years ago, when Shell Oil was so muscle bound that it hads to contract out all its drilling work in the East Texas field, because the bureaucracy could not process the number of requests from its field superintendents. Every decision had to go through four managers between East Texas and Tulsa. many of them who had no clue about what needed to be done. This mentality, I understand, still hampers the efforts of the Majors to get into the Russian fields.