Questions about costs can very well be problem-solving questions.
You see, when a person is faced with two apparently similar pieces of computing hardware , but with a great disparity in cost, it is often (though not always) the case that there are some significant technical differences between the products. These differences have bearing on the usability of these products for the person - speed, reliability, durability, flexibility - and maybe even their very compatibility with user's setup to begin with.
Thus, helping a person understand differences in cost, or in some cases, surprisingly high or low cost of a product, helps the user solve the problem of deciding on the appropriate piece of hardware to use/buy. And this can well be done without deteriorating into opinion-based product recommendations.
More generally, it helps improve readers' understanding of the kind(s) of hardware being discussed, their inter-relations and their inner workings.
Note that such questions appear to be primarily focused on the costs - that's what the question text may mention exclusively - but they really aren't.