First things first, let me cop to the fact that this is self-serving. Shocking, isn't it, that the company that provides custom websites thinks you should avoid "the competition"? Obviously we have a vested interest in convincing people that an actual website design and development company is a better option over going the "low cost" route. I'll try and make a case below. However, some of it you'll just have to trust me on.
Why You Should Avoid Friends and Family
There's a few reasons really. Many of them extend from the general rule not to "mix business with relationships." There's lots of room for bad blood. People can get their feelings hurt because someone else thinks their services are only worth, "I'll owe you a beer." Even if you offer to pay the person might feel bad about charging their normal rates, if at all. If you're not happy with the work where are you now? You can't just tell them.
There are lot of ways it can go bad, but I'm going to focus on one in particular, since this one applies even if everything goes smoothly: You might not get what you want when you want it. Not because the person isn't capable, or screwed up. Because every time you want something done, every time you have a question, etc, you'll have to wonder if you're "bothering" the person too much. When is the last time you worried you were bothering your cable provider too much when your service wasn't what you expected? If you're paying a company you have no personal connection with the transaction is easy. Yes, we'll charge you to make changes, but you won't have to feel conflicted about our relationship and you'll never have to settle for things being not what you hoped.
And that all assumes the person knows what they're doing.
Why You Should Avoid "That Guy who can make Websites"
I'm sure it's true of all industries, but as a member of this one, I know for sure the "fake it 'til you make it" crowd is out in full force. There are a number of people out there that make a website in a class, or for some other purpose, and then fancy themselves full-on web developers. They set out to make a career out of it, and find themselves almost immediately in over their heads. Ironically some of this crowd that know a little bit more can be even worse. These people generally know just enough to be dangerous, loosely hooking up examples they found on the internet and copied on to your site, which prolongs the amount of time they keep you on the hook for. Don't get me wrong: I don't think these people are con artists. I think they honestly think they can do it, and just don't know what they're getting into. Then things quickly spiral out of control.
We've gotten a number of clients where one side or the other finally admits defeat on their current website, only to find out they're lots of money in, and it's completely unsalvageable work. In most cases we wind up redoing all or most of it for them anyway, and almost always for less than they have currently invested in the non/barely functional version. Obviously there are some people independently making websites that do excellent work. There are also some totally-have-an-office-and-employees-and-everything companies that will charge a lot and do sub par work. For the most part though, the same adage applies to creating a website that would to an auto mechanic. You get what you pay for.