I'm also such a "Money-Primter" by myself, and doing it also for business (not large business, but 25TH is at least a big hobby....for me more a small businnes) and I also have to pay the high electricity bills here in Switzerland and still I would be able to wait a few hours or even 1 or days to trade my coins,when I will get then 50, 80 or more USD more. And since the BTC market reacts very fast compared to other markets, this woud not take long (as I described before) FOR THE PRICE TO CLIMB.
You might be overestimating how much the market can be moved by miners. If bitcoin was something like oil or food - a necessity that must be had at almost any price - temporarily halting the supply would quickly hike the price. But it's not time-critical, not a necessity, and if the price goes up, the buyers can simply stop buying and either wait, or stop buying forever.
But the point is that enough people must come to the same conclusion, but I feel that people today are in the mood "Better I sell all now, price could be less tomorrow" and this is the reason that in the end then really puts the price downwards.
On the Oilmarket or Soja or Aplle-Shares we (the people) do not really have it in our hands to change the market in some way, but on BTC Market we would.
Just still the problem how to get enough people together for a coordinated action....I'm sure it would work...BTC's were always bought, at 1000, at 800, 500 or 300...they were bought, so if sellers stop putting them on the market for less than a certain price, they willbe bought as well, maybe with a short downbreak os trade volume, but I'm sure this would only last some minutes to few hours..
What you are describing is done all the time IRL. Think OPEC (bunch of oil "miners" getting together and agreeing not to undersell each other), or even trade unions (a bunch of proles getting together and promising not to underbid each other).
And it works, but only when the stuff being sold is a necessity. Bitcoin isn't.