Supercool the Forbes link you quoted is per capita, As most of the population in Qatar consist of Expat who are contributing heavily in running this country do not count when it comes to the GDP per capita only the indeginous 300k Qatari get considered.

Where as Painther is quoting the overall GDP.

Also why do you only want visa on arrival to the UK when the US and other EU countries you need visa before you fly also? What is that attracts the GCC citizens to UK?