You have photography plan purchased in 2013 at special promo price (CS3+ owners), the cc is eligible to access & browse the market but not download it
Creative Cloud Help | Creative Cloud Market
What’s changed between Adobe’s new and previous Photography Plan offerings? The new one has 2 GB of Creative Cloud file storage rather than 20 GB – but instead you get unlimited online photo storage in Lightroom Web. The new generally-available plan also does not include a Behance ProSite (however, subscribers of the previous promotional program are grandfathered in on both the ProSite and the 20 GB cloud). But outside of that, everything else is the same – including Adobe’s flagship Photoshop and Lightroom desktop applications.
So if you’d like to have those industry-leading professional imaging tools plus other benefits at a low monthly cost, this is a terrific package… And if you want to take it up a step further and get the full Creative Cloud including these and all the rest of the new CC 2014 tools, then existing CS customers can receive upgrade pricing for $29.99 a month.
Regards
Rajshree