I am reaching singapore at 1850hrs and my connecting flight is at 2005hrs from singapore, so practically about 30mins to spare, can i by any chance be able to visit Mustafa center to buy an item or do i have options of ordering the item and getting it shipped to the airport...
Singapore may be small but no, there won't be enough time for you to head to Mustafa in such a short period of time. I'm not familiar with Mustafa so I dunno if they can arrange for you to pick things up at the airport but I seriously doubt it.
I'll recommend you just have a walk and look around the airport, afterall it's one of the nicest in the world I think!
As far as I'm aware, Mustafa centre don't do delivery or shipping, it's more of a place that you see what you want and you buy it.
With that timeframe you wouldn't have time to get there and back, you'll have to make do looking around the airport as Sapphyre says.