Do Curt's original pages fetch anywhere near the figures of a Neal Adams or Jim Lee page?
No, thank Rao! I wouldn't own one if they did (the Kirby I own was purchased back in the mid-80s but my Swan was bought only 5 or 6 years ago, long after Kirby pages had become too rich for my meagre resources).
Besides Perez, Dave Sim is another artist who has studied Swan and praised his talent. Any others?
It does seem that even older fans tend to slight Swan for the reasons you mention --but I wouldn't be surprised if he showed up in many fans' Silver Age top 20 artists, for instance. Along with Dan DeCarlo and Kirby, I consider Swan among my "Holy Trinity" of 1960s mainstream cartoonists. There are many many others I love, of course, but those 3 sum up the decade for me.