Whats the cheapest way to get lounge access at IAH

I am flying through IAH in October and am looking for the cheapest way to get lounge access. I have seen the priority pass, but I am likely to only use this once. So for me and Mrs B to use the lounge with prioirity pass would be £99 right (£69 to join and the £15 each to get access). There surely must be a cheaper was to do this.

Any siggestions?

Paul

Moderator locked topic to avoid duplication of Paul's later posting "Priority Pass"