There are many ways in which you can monetise a membership website, including charging for access and using carefully chosen affiliate linking strategies.
The link above is a demonstration of how you could run your business website, with no extra pages or bells and whistles. The fact is that the sky is the limit when it comes to functionality; you could add features all day long, so it really comes down to what functionality you actually need.
I can offer you all or any functions or services you may require, but you need to be aware that I am using free versions of software to power the demo sites, and upgrades can range from around £20 to over £100, depending on requirements. The upgrades are purchased directly from the supplier, either by yourself, or by me. I would charge a nominal hourly fee for installing and customising them to your specifications.
Please feel free to contact me for further information.