I don't think there is a rule.
This forum where you are posting is actually their paid space.
More like etiquette.
Perhaps Rangeview Sports paid more for these.
I've noticed some really good deals from Rangeview previously.
If you want to let someone know of a cheaper price,PM them.
Or just say there is cheaper alternatives and let them research it.
As to availability, one of the mentioned dealers doesn't have stock and the other only has one.
Yours is an interesting perspective, and to be honest you could be right... but my initial reaction differs. I think if you post to a forum (your paid space or not) you should expect discussion. In this case the discussion was about their price point vs the industry standard price point. There are lots of other marketing options where there is no discussion. I noticed someone mentioned you should conduct yourself in a companies forum the same as you would in their store. I would have no issue going into there store as saying "hey guys, love this rifle would you consider selling it at the same price as some of your competitors?"
Yes, almost every store sells out of these rifles within a few days, and I think that was the initial point of the post. These are an in demand item but it is frustrating when a company increase a price over MSRP just because the rifle is in demand.