This will be my first time to visit bangkok. I've been to phuket ones. I'm pretty sure the cost would be different. How much do i need to bring as pocket money ( airfare and hotel excluded) ?

Say i go to massage spa, bars and usual tourist atrractions?

 

Will love to hear any suggestions

Doing all that...

I would suggest 3000 to 4000 baht a day. You might need more if you plan to take boys back to your hotel.
You can blow 500baht a day on tourist stuff. Paying into temples ect.
200 - 500 on transport (taxis - tuk tuks) - althought the BTS is cheaper. 
Depending on what you eat I would have 400 to 800/1000 a day for food. 

Bars are expensive. Anything from 100 to 120 for a beer, 180 - 220 for cocktails. If you plan to go to gogo bars, up that. 350 - 480 baht per drink in there. How much money you would need would depend on how much you drink? If you want to get drunk, 2000+

At the end of the day it comes down to what you want to spend. We can't answer that for you. 
You can live in Bangkok on 300 baht a day. I often do....
You can also easily spend 20,000 baht a day. I know some people spend even more than that! 




 

Thanks samebb! This is very helpful.