Spectrum,
It all depends on what sort of a contract the sales people are working under. Generally any sort of commission is calculated as a percentage of the profits on the sale, not on the sale price of the item. That being the case, the lower the profit, the lower the sales persons commission check. Some salesmen do get a flat percent of each item sold, but in those cases that commission is already built into the items price and the sales person usually don't have a lot of leeway on pricing. It really varies a lot from industry to industry and company to company.
When it comes to company owners pay, they generally take their money out of the business in three ways, only one of which is directly effected by the current periods profits. First, they pay themselves a salary as CEO or some other officer of the company. Second, they have various personal expenses that they can funnel through the business and treat as business expenses. Cars, insurance, cell phones, etc. They don't get to write the full value of the item off at tax time, but it's still reducing their taxes instead of being treated as income. Finally, they take money out of the company in the form of bonuses. Those can occur anywhere from monthly to annually, and since the amount available for their bonus is directly related to that periods profits having a bad month, quarter, or whatever can make quite a difference.
Keep in mind that smaller businesses tend to have more cash flow issues because they don't have the sort of strategic reserves that larger companies can muster. The smaller the business is the closer to the line it tends to run. In those cases the owners have to watch every penny like a hawk and they can't afford to pay themselves much more then they do their employees, and they pick something that's sensible and has a reasonable price to serve as their company car. It's only when the business starts to get big enough that they don't need to spend every minute drumming up business and making sure things run right that the salaries start to creep up and the perks start to become questionable (well, at least if the owners have any brains).