I have a Diners Club credit card. For the cost of $A90 per year card fee I get access to Diners Club lounges around the world (Check the Website for a list). They have lounges in most major UK airports and in Dubai. Its probably the cheapest access to lounges you can get.

In Dubai there is the first class lounge between gates 112 and 114 (Terminal 1) and the Marahaba Lounges that provide paid access. These cost between 60 and 120 Dirhams paying at the reception. The first class lounge is very good standard of facilities, food and drink and great if you are not flying Emirates and leaving from Terminal 1.