Different prices for Gold ETFs

Hi

One clarification please

The prices of gold etfs listed on NSE vary from 2450/- for Reliance Gold to over 2670/- for Motilal Oswal

http://www.nseindia.com/products/con.../etfs/gold.htm

I think all of them represent 1 gram of underlying gold

Why this huge difference ?
Any ideas ?

Thanks for advising