I agree with the shopping and pricing part as it is indeed volatile. But I think that we should re-evaluate the whole ban on product recommendations. Stack Exchange and particularly EE.SE seems like an ideal forum for product recommendations, because of the voting system.
Component selection is a huge amount of work in any electronic product design. It takes so much time, thought and energy, and the outcome is not certain. This would be a great community to answer those sorts of questions. The combined expertise of this community is overwhelming.
The reason stated to dismiss these question is that "they are rarely useful to others and quickly obsolete". Is this really the case? It's quite often that if someone wants to design a product to do XYZ, there are also others that want to design a similar product. And if at sometime someone wants to design a bit more esoteric product, what's the harm in asking?
Obsolescence wouldn't seem to be much of a problem. Usually components are available for decades. And when they do become obsolete: no problem. Someone will write a new answer that describes another part that can replace the obsoleted part.
The same goes for "opinion-based" dismissal. Yesterday there was a question that sought to compare the different ARM toolchains. Very interesting question and what better place than this to ask this question? I for one would have welcomed a lot more opinions on the matter before the question was closed.