The system is generally fair. Paying a policy maker for their vote or decision is illegal. It is also illegal for lobbyists to furnish policy makers with lavish meals or provide access for them to "luxurious locations". People and organizations with money do not always win.
Fairness questions also arise when some lobbyists have easier access to lawmakers than others. Friends, former employees and colleagues all may appear to have special access to a policy maker. The way I see it, the rules make people feel better about the system.