It costs more per GB than SDHC cards because it is old technology that isn't the gold standard anymore.
I didn't buy it for that reason though... I bought it because I needed to expand the storage on my TomTom. I have a GO 510 that is still going strong after 6 years but doesn't accept SDHC. The included TomTom branded SD card was only 256mb and I needed expansion to add some updates and features.
All I needed to do was format the card then drag the contents of the old card onto the new one and it worked straight away, recognising all 2GB of storage.
Perfect purchase for that purpose. If you are in the same boat that I was (needing to expand storage in an older Sat Nav) then I recommend highly.