Help me find a windows phone

Hey tribe, I have a Nokia 5230 and I am planning to buy a new one. I am a big fan of windows and have a windows 8 pc too. I want a Windows Phone, my budget is around Rs.15000(240 USD.). I was looking at lumia 625 but it has 512Mb RAM and i dont know whether it will be compatible with future updates. I totally love the 820, it is an awesome phone.

My question is whether I should by something like 820. Its still old or is Nokia going to release a Moto G kind of phone.