5130 is great but do get good quality aftermarket earphones. The default ones are extremely horrible and I still wonder how nokia's music phones have worse earphones compared to entry level radio-purpose earphones on samsung's 2k phones.
Luckily for you, all that may well fit within the 5k budget.
I used this phone for nearly an year. Problem with this phone is the firmware is buggy. Upgrade to latest to solve this particular issue.
Also default memory card of 1GB is tiny. Get a 16GB card if you want to listen to lots of music. This also adds to cost.
All in all, I think even a Nokia 2690 will do if all you want is music and don't care for much else. You can attach a cheap aftermarket "controller" or whatever its called which is similar to the one in nokia 5800 if you want dedicated music controls.
And on the higher end, Univercell.in sells the LG KP500 Cookie for 5k. Its a very good entry level touch screen phone and is ahead of N5130XM in all non-music related activities due to large screen, esp stuff like internet browsing and video watching.