HTPC + NAS as cheap as possible

1. What is the purpose of the computer? What all applications and games are you going to run? (Stupid answers like 'gaming' or 'office work' will not work. Be exact. Which games? Which applications? Avoid the word 'et cetera.')
Ans: I want to play a full HD 1080p with DTS tracks. The bit rate will be around 15 MBps. No games. Will be using xbmc. And part time as NAS. This system will run 24/7 mostly.

2. What is your overall budget? If you can extend a bit for a more balanced configuration, then mention this too.
Ans: as cheap as possible. Rs. 10000 max limit

3. Planning to overclock?
Ans: No

4. Which Operating System are you planning to use?
Ans: XBMC

5. How much hard drive space is needed?
Ans: None. I already have a 1TB + 500GB + 160GB

6. Do you want to buy a monitor? If yes, please mention which screen size and resolution do you want. If you already have a monitor and want to reuse it, again mention the size and resolution of monitor you have.
Ans:No. Already have a 55inch full HD HDMI TV from LG.

7. Which components you DON'T want to buy or which components you already have and plan on reusing?
Ans: Dont want hard disks, moniters, cabinet and KB & mouse

8. When are you planning to buy the system?
Ans: next month

9. Have you ever built a desktop before or will this be done by an assembler?
Ans: I have built 3 systems. Specs in my signature

10. Where do you live? Are you buying locally? Are you open to buying stuff from online shops if you don't get locally?
Ans: Chennai. Possibly want to buy locally. Online shops are last choice. Buying a PC for the first time in India.

11. Anything else which you would like to say?
Ans: Just need a good motherboard, processor, Ram and PSU
I already have a good 55inch TV.
Denon receiver with 5.1 technics+yamaha speakers
Just need a good x86 HTPC. Dont need android systems. I have already tested with Raspberry Pi.