As a reader you wouldn't be weirded out if the first section of the article was to justify why an affiliate link was used?
That would annoy me as a reader a lot more than having an affiliate link used without mention. I mean, I'm not sitting there trying to trick people into clicking links. The blog post is just an honest look / opinion on the keyboard. If you decide to click and buy one, that's cool. If you close the article in 5 seconds after skimming around, that's cool too.