This is actually an interesting question that I've never really thought of. What you are essentially describing is a monopoly on the side of the consumers to artificially drive down quantity demanded in order to lower prices.
You didn't state many details in your question but I'm assuming that the good in question is inelastic, is subject to competitive pricing, and has it's current price in competitive equilibrium.
The outcome of consumers collectively refusing to buy a product above a certain price would have the same effect of monopolistic pricing of a firm but in reverse, there would be a shift of some producer surplus into consumer surplus as well as the creation of dead weight loss as some producers are priced out of the market creating shortages.
This could also be empirically the same as the creation of a price ceiling for the good. If collectively consumers refused to buy a product above a certain price then that product would have a price ceiling and producers would produce at that price in accordance with their own supply curve.
As for your question about whether it would be a "good idea" that depends on what your definition of a positive outcome is. This type of action would have the effect of transferring some of the producer surplus to the consumers which would benefit the consumers but it would simultaneously lead to less production on the part of the producers due to the lower price creating dead weight loss and shortages. Empirically this would be bad for the aggregate economy as a whole due to the loss of surplus to dead weight loss, however, depending on the producer supply curve this may or may not lead to an aggregate gain in consumer surplus. An inelastic supply curve would lead to a gain in aggregate consumer surplus while a elastic supply curve would lead to a loss.