I think the popular conception regarding the rarity of red haddonis and the price they therefore demand are very much out of touch with the reality of supply (at least on the East Coast of the U.S.). Although things may have been different years ago, IMO, today, red haddonis are not nearly as rare as they are chalked up to be. I typically see one or more available in at least one of the LFSs I frequent at least once every month or two and they are regularly available online. IME, it is actually much harder to find true blue or purple haddonis than it is to find reds, but they perplexingly command lower prices than reds, likely due to popular misconception regarding rarity and the attendant "mystique" of reds. Nick also correctly points out that IME, giganteas of any color are indeed rarer than red haddonis, yet they often sell for a fraction of the price.
This issue has perplexed me for some time and it will be interesting to see how long it takes the market to respond.