I've seen a few comments (in different places, although of course heavily on the Singh-Ray website) that a gold & blue polarizer should be considered a must-have for a landscape photographer's filter set. Unfortunately, as a hobbyist who has only sold two or three photos and who shoots mostly for fun, I can't justify the $240 for it.

Are there any reasonable but much more budget-friendly solutions? I see that Cokin has a yellow and blue polarizer (Cokin 173) that can be had for less than $50 and might be comparable, but I'm not sure. I've also heard the suggestion that a gold and blue polarizer is really little more than two CPLs and that you can stack two of those to get the same effect with the tradeoff of a little vignetting at the wide end. Any other ideas?