It seems that Nokia is all set to launch 3G variant of Nokia Asha 501 which are codenamed as Pegasus (Asha 502) and Lanai (Asha 503), courtesy to @evleaks.
Nokia has launched Asha 501 in a global launch here in New Delhi, at the time of launch Nokia has told that they might launch 3G version this phone.
Asha 502 and Asha 503 will have some improved specs like camera. Out of these 2 phones one will be single SIM and other one will have dual SIM option.
Nokia has to price these phone below $100 because at $100 you can buy smartphone like Lumia 510.