Bikes appear to be simple machines. You can see almost every moving part on them, so they don't seem as mysterious as a car or refrigerator. But there is enough going on with bicycles, enough to know about them, that people (such as myself) make bicycles their careers. It takes a long time, and a lot of (expensive) mistakes to get good at bike service. You don't know that the Deore hubbed wheel you bought on Amazon won't fit on your track bike until you do it. You're going to spend $15 on a chain whip you don't need, because you have a freewheel. Your going to have to buy extra front derailleur cables, because you'll fray them from too many adjustments. And that's all ok because that's how you learn. But it's not cheap.
There are lots of things you could do to save money. You could make your own clothes- fabric is cheap- but you probably don't. Unless you enjoy doing it. You could bake your own bread- flour is cheap, yeast is free- but you probably don't do that either. Unless you enjoy baking (and yeast hunting). If you're not having fun, you're wasting time and money on a pain in the ass activity.
Back to the folks who like to tinker- there are tons of resources for home mechanics. I'm sure you already know about the internet- which is great and has some good nuggets of information. It also has giant boulders of bad/mis information. So where does one go for easy to find good, reliable information? (Here comes a not-so-subtle plug) Your friendly, local bicycle shop. That one guy on that one forum can't tell you what's compatible with your bike, but I can, because you can bring it into the shop where I can see it and we can talk about it.
Really I just wanted to say, if you don't want to work on your own bike, don't feel any pressure to do it. You aren't a bad bike owner, you're just good at not doing things you don't find fun. If you do find it fun, and you want to tinker- do it! And use your LBS as a resource.