My family has a small apple orchard here in Washington, and farming is a
tough business.  It's true that if you pay a retailer more, that has
absolutely nothing to do with what the grower gets.
However, your point is well taken that market pressures have a very
significant impact on what growers plant.  These same relatives of mine have
had to pull out all their Red Delicious apples (much of the orchard) because
nobody buys them any more, and they don't make enough to cover growing
costs.  They planted other varieties that are in high demand.
So yes, if we and lots of others only buy genuinely good beans, word will go
up the chain and growers will respond.
- Anthony