I feel compelled to say this every time the topic of sampling comes up, but...
You should buy cakes. Puerh is not green tea. People have relationships with their teas as they grow older. Sometimes good, like a toddler in a good mood. Sometimes bad, like a sullen teen.
And in general, I think that the chief cause of people having cakes they don't like is *because* they sampled too much. Remember, the majority of tea made isn't going to be bifurcated into good or bad. Much of the tea you try will have *something* good about them, and a n00b isn't going to know how to balance what's good about a cheap cake with the understanding of *why* it's a cheap cake. That understanding broadly only happens as you try to *drink* the cake! So you can sample and sample and sample--while still making mistakes in buying cakes after all of that sampling. Racking up expense given how expensive most samples are.
Five one-oz samples, say, from Yunnan Sourcing US probably costs a few bucks less than some pretty decent cakes there (samples of the house cakes are cheaper than, say Hailanghao). It's just a vastly better idea to buy a cake, say 2010 Youle Ya Nuo 250g @ $24 with a buck or two shipping, and explore what you like and don't like about that cake, while buying fewer samples. Complement that by reading as much as you can about puerh, and as many of the reviews as you can. When trying a tea you're very familiar with, you can connect some of the ideas that you read about online, with what's going on when you have your session. It's hard to do that when you're going ounce-by-ounce of what can be radically different teas. You're also less misled when it comes to how various brands handle their tea-making. Dayi, Xiaguan, Douji, they all have house flavors, for example, and once you know one, you broadly know them all. Lots of samples can tell you that, but it's easier when you have a baseline of familiar teas.
It's just a better decision to buy an (some) easily affordable "mistake" in advance, and fewer samples as a result, and really get to know at least one tea well. You *will* have tuition tea. I technically don't have any shengs I hate, for example. My *worst* cake is a 2003 Xiaguan Baoyan, and that was $19. I avoided this largely because I spent most of my money on expensive brands that turned out to be worth it. I've bought zero cheap Dayi, one cheap Xiaguan...zero cheap Bulangs and "Yiwus". Thus, tuition tea, for me, has been all about opportunity costs. My biggest failure in terms of opportunity costs were in buying as much Nada 2010 as I did. Not because they weren't pleasurable teas, but because better teas were available then that aren't available now.
If I had any advice for buying tea? Take good care to understand why the price is the way it is. Understand that most everyone in the East has a good grasp on the price structure of acquiring cakes. After all, they've had to buy the leaves, press the cakes, market, you know what. They've had to pay for storage as well. Also understand that there is a strong Gresham's Law in effect for puerh. Good to excellent cakes are retained for favored customers or personal consumption, and bad cakes are pushed with all the vigor people can manage into the marketplace. Lastly, there are a variety of cons that people use to get you to buy their over-priced cakes--and getting people to buy horrible cakes for $10 is a classic. If you understand about what you're buying, it's perfectly possible to buy decent Nanjian, for example, for $10. It's boring, stuffy, meant for cheap consumption, but honest cheap consumption, and you'll actually have days when you're happy with cheap Nanjian, Fengqing Factory, Xiaguan. So try to educate yourself about the market, and read as much as you can about the various reputations (factories, tea producing regions, etc), and then you'll be able to find great teas that are much cheaper than they should be for whatever reason. Or you'll know just how impressed or disappointed you should be when you try that sample.