SoftUK are selling "Lost Empire: Immortals" for the PC for £9.99.
Use the code "Cheap Games" (without quotes) to get free delivery.
You can get cashback via some sites (e.g. 2% Free Fivers, making it £9.79). You can also get 6% cashback through SoftUK's 'Collector' program
£16.49 is the next best price, from PowerPlay Direct.
PLEASE NOTE: SoftUK has recently had periods of time when the site has been down, so if you can't get it to load, try again later. :-)