I think you can definitely build your own site. Wordpress is a fantastic platform to use and is completely free, and registering with Google Maps is free and takes about 15 minutes and can get some good results.
Getting the site showing up on page one isn't too hard once you know what you're doing (I've done it for 40 tradesmen in the last 7 months) if you:
a) Choose a website domain that matches what people search for - e.g. plumberinfeltham.com rather than markhattonplumbing.com
b) Register the site in as many of the free directories as possible. This is not necessarily to get work from them, but they will help boost the ranking of your site. It's also the quickest way to get yourself showing up multiple times on page one (my record is 6 times in the first 7 results!) Some of the directories rank really well, and are indexed by Google every few hours so you'd be crazy not to add your listing in them as it only takes a few minutes.
c) Use Wordpress (Google loves it) and don't get too spammy. Google's latest update penalises sites that try too hard, so just be sure to mention the service and main target area plenty of times and leave it at that. Stuffing meta tags does more harm than good.
Lots of site-builder type sites use flash or are really poorly-optimised and don't tend to rank well. No point spending time building a site if no one is going to find it, so I'd recommend learning Wordpress. It doesn't take long and is really useful once you can do it
d) Make it personal and friendly. I've found that sites written in first person from the tradesman themselves convert visitors far better than generic sites that try to sound to business-ey or corporate. People buy from people and their main thought is "is this person genuine".
That's why those horrendous Thomson Local and Yell sites are such a washout for their owners. Also be sure to get some testimonials on there. When new customers contact my tradesmen clients they always say that the testimonials were the reason. And they're so overlooked by most web design people who don't understand the market or mindset of the people visiting.
For those reasons pictures of you on the site work well, even if they're just basic phone photos (at least that looks genuine).
There's really no reason to have to pay anyone loads of money to do it for you if you're technically minded and have the time to learn, and I'd be happy to show you some tradesman sites that are doing well for their owners if you want a template to work from.
But the most important thing is to just do it. The results you can get from a well optimised site showing up on the first page of Google are incredible. Any electrician or other tradesman's site - no matter how homemade it looks - if it shows up on the front page, it will get a lot of clicks as most of the other page one results are directories and people don't tend to click on them.
Hope that helps! Been sat typing watching the football, wrote a little more than I planned to
Tim