What about a Palit 9800GT 1GB and that new PSU, instead of a GTX 460 or HD 5850?
http://www.pcgameshardware.com/&menu=browser&image_id=883991&article_id=657567&page=1&show=original
It will simply destroy a 9400GT, looks good w/ your prices, and wouldn't be
too limiting by the time the rest of the system got in place. By then, nVidia will have certainly gotten more new cards in place, and both next gen series will be reasonably priced (or the current series made far cheaper), approximately evening out the end cost/performance.
By the time you can save up for the CPU, mobo, and RAM, you could probably get something with the performance of a i5 quad, or maybe better, for the price, rather than having components sitting around waiting to be used. While graphics of this last year or two have been rather strange, on the CPU side of things, AMD and Intel are very much competing. There is good value in CPUs right up around $250 (12k rupees?), prices have been neatly dropping month-over-month as you go up, and performance has increased month over month, on the low-end. Even considering foundry problems for AMD, there's no reason not to expect a good showing from both AMD and Intel, next spring and summer, when you would have saved up enough for the rest of the system.
If you're not going to have the whole new PC before Christmas, but plan to have one it by the middle of the next year...don't spend a ton on a graphics card, and save up enough to buy CPU+RAM+mobo all at once.