Here's a good article about why budget Android phones aren't worth it -
Why Midrange Android Phones Aren't Worth the Sacrifice
Android isn't optimized for cheap hardware so for 15k forget about getting a good deal on 'The Google Experience'.
For that money, Wave (original) is as good as it gets hardware wise and if you can forgive poor app support , its a pretty decent smartphone - it does office files, great browser, superb display and build, multitasking, best in class camera and camcorder performance, good audio quality, great battery - in short it's a 'complete' package out of the box. But once out of the box, there's little you can 'add-on' to it.
And that's where Android trumps it. With it's huge app support and comitted rooting community you can have some serious 'fun' if that's how you swing! As pointed out, to get a good deal on Android, increase your budget to 23k and you can get some great future proof phones - Galaxy S, Galaxy SL, Desire S etc (in that order).
So it all depends on you, your usage, your previous experience (first time smartphoner or a pro) and your budget.
If you CAN'T strech it to 19k (the price of Galaxy SL) and hate NOT having millions of apps (as is and will be case of Bada) BUT want great hardware may I suggest (rather controversially!) that you also look at the latest Symbian S^3 phones? Here's why -
*The new PR2 update (Symbian Anna) has really upped the game for Nokia as a competition in smartphone OS arena.
*Good app support in the ahem grey areas of the web if you know where to look!
*AMOLED display, solid build.
*Unbeatable camera and battey performance.
*Symbian is very hardware optimised, so if you think 680MHz processor is 'low-end' also consider that most of S^3 is GPU driven by BCM2727 chipset - better than iPhone 4's GPU in horsepower!
So for Nokia, I suggest N8 or if you can wait, its cheaper variant T7 (~19k).
Peace.