The biggest etailer in the UK has three pieces of Corsair Corsair 2GB DDR3 kits. This pretty much explains how many modules are around.
The production is not that big issues, it is more about the price as in the UK you have to pay £352.49 inc VAT for 2 GB kit. For our American readers this translates to almost $700 or €512.
Just for a comparison you can but 2 GB of Corsair 2GB DDR2 XMS2 Dominator PC2-8500C5 TwinX (2x1GB) for £129.24 inc VAT and this is still considered to be very expensive for DDR2.
So you have a choice to buy 2 GB DDR3 or 6GB of DDR2 for pretty much the same price.You can buy this spicy DDR3 here.