So the Yongnuo setup is no doubt the cheapest, but you may suffer from reliability issues, and good luck getting the product repaired in a timely manner if you do. A great setup for a budget amateur, but don't count on it when you need to use it hard every day.
I respectfully disagree. Plenty of professionals rely on many other brands than Canon and Pocketwizard. Equipment fails, and there's no evidence that Canon or Pocketwizard equipment fails less often. Sure, the warranty work is probably easier and quicker with brands that have direct US presence, but honestly, if I have a ~$100 flash fail, I'll buy a new one while the other one is being repaired. It's cheap enough to be able to do that. Canon needs good warranty service on their flashes because their stuff is so doggone expensive, even though it's probably manufactured in the same factories!
I shoot weddings exclusively with 3 Canon 600EX-RTs and I am very happy with the performance. I would eventually like an AlienBee or Einstein for on-location portraits in bright daylight, but 600EXs perform so well that I've found I don't really need to buy anything else. Canon RT -- expensive? Yes. Ridiculously so? Not really.
That's great, and I would never criticize anyone for their gear decisions, but many, many photogs use "other" cheaper gear and get the results they're after. It's a cost-benefit analysis that everyone has to do for themselves. You chose one way, I chose another. Don't look down on me for that or accuse me of being too amateur. (I know you probably didn't mean it that way.)
I'm not a total cheapskate. I buy Canon L glass and full-frame bodies. I'll spend a bunch of money on new things when they offer a significant benefit, but when I see something that Canon charges several times more for a negligible gain in quality, I call it ridiculous and go the other direction.
Look, I guess my main point is that shot-for-shot, these set-ups are mostly equivalent. Of course equipment can break. Firing a flash tube is an electrically violent process, and flashes can and do fail, regardless of brand. The warranty is great, but it doesn't protect you in the field. The only way to really prepare for failures is to carry spares. With my YongNuo's I can afford multiple spares, but it's painful to buy spare Canon speedlites.
To each their own - just trying to point out viable alternatives. Canon is great! All hail Canon! :-)