I get about 5-6 down and bout 2-3 up normally with 3G so I am quite content. Espesially with 5gb a month costing 50£. But just a note though if you want to switch to 4G you may be able to since EE is the parent of Orange.
Are you sure of your pricing, that you are comparing the unsubsidized prices, not the subsidized (which are locked to a US carrier). The UNLOCKED 64 GB iPhone 5 in the US is $849 + sales tax. In NYC, for example, the sales tax is 8.75%, so that adds $74.29, total cost is therefore $923.29.