My point is, a lot of keywords fall into the e-commerce terms category. I'm not talking about general terms like "wireless routers". A lot of them are more specific.
This becomes very relevant as what you refer to as "buying keywords" are often also dominated by big e-commerce sites.
Ex: gaming wireless routers are buying keywords, but "<brand> gaming wireless routers", which I think you'll agree are even better keywords... but the latter is most likely dominated by all e-commerce sites.
What I'm trying to say is I can rely on any keyword tool anymore, no matter how good all the competitive indications are. It's a must to take a look at the SERP and see if there are forums, other affiliate sites, etc. that are easier to conquer.
The problem with this type of keywords is, even though all indications say it is easy to rank, Google seems to make exceptions and only choose sites selling that product.
Of course, I hope I'm wrong. I hope I can only look at all competition factor, but it isn't anymore.
My experience seems to be the same as the article I posted above.
Or do you able to conquer those keywords with your SEO strategy?