That depends on the company. Most companies are constrained by their Personnel policies, which have been crafted over years by the contending forces of labor unions, legal requirements and precedent, and financial considerations. That means they aren't easily changed. If the world were perfect, you could walk in an negotiate what they will pay you per hour and what benefits you want, but most companies have already established how many people will be hired and at what rates and with what benefits - in order to be able to construct their payroll budget. So they won't deviate from the figures they used for budget planning, because they figure if they start deviating, they'll never be able to keep track of what has been changed and what the implications of those changes are - and consequently they'll exceed their budget and possibly endanger the whole company.
So ask if you can decline certain benefits, or if you can elect to work at a lower pay rate. They might say "yes" but they probably won't.