Thats a good enough answer for me mate.
The RS Tuner is close enough on a standard car (with a better exhaust) generally that there really isnt much value in bothering to pay the extra for a "custom" map.
Ie, 100 quid to solve the sub 5K hole is money well spent, another couple hundred on top to try and chase down just a couple of bhp isnt really.
Secondhand ones seems to be priced a bit mentally, you can buy new for only about 160 quid, which often works out cheaper than buying secondhand and then buying a license and map!