Should I buy premade software or hire someone to write it?

Background info: Hi, I could probably also put this in the web development section, but here goes. I want to start a small business/website. I am new to all this. (I am not a programmer.) I think I can create all my own webpages, except that I need a database and search/matching capability (similar to, but not, a dating site), and I do not know how to write that kind of software. I'm working on a tight budget. A reputable web hosting company thinks they can create what I need (plus the rest of the site) for about $3k. But some people say that I will not wind up with what I want. If I request that they develop it on an online server so I can monitor what they are doing, would that help?

Questions: Would people recommend that I buy a premade software like osdate or hire someone to write the software? Is there other software that I could buy for this purpose that people recommend other than osdate? Is 3k alot of money or not enough to get anything worthwhile? Any and all comments on this greatly appreciated!