Though Nvidia has labeled it as OEM you can buy it - Infact every manufacturers like Asus, Galaxy, MSI, Zotac, Palit, EVGA has released their own version of GT440
Newegg.com - GT440
Though note that the GT440 available now is different than OEM GT440 :
GT 440 OEM :
CUDA Cores : 144
Gfx/ Proc Clock : 594/1189 MHz
Memory Configuration : 1.5GB/ 3GB 192-bit GDDR3
Memory Speed : 800/900 Mhz
Power Connectors : 6-pin
Length : 5.7 inches
Maximum Graphics Card Power : 56W
GT 440 :
CUDA Cores : 96
Gfx/ Proc Clock : 810/1620 MHz
Memory Configuration : 1GB 128-bit GDDR5
Memory Speed : 800 Mhz
Maximum Graphics Card Power : Minimum 300W PSU
Now compared to GT 430 :
CUDA Cores : 96
Gfx/ Proc Clock : 700/1400 MHz
Memory Configuration : 1GB 128-bit GDDR3
Memory Speed : 900 Mhz