Rubbish, there are 2 reasons they are so cheap:
1. They sell millions of these so can buy in bulk where as a tuning garage only gets a few customers a week
2. The designer obviously has a love for cars and is helping out the people who feel the same by not giving it a ridiculous RRP tag.
As givememorepower says, he has 4 and is running over 400whp!!!!!! I bet its not too good on fuel but the figures are the proof!
My funds can only stretch to one at the minute but I'll get my car dynoed and show you. Only problem is I have added a roof scoop and sideskirts since then so you'll have to take off the 15bhp that they have added off my final result.
You really need a carbon wing & carbon light covers to complete your power gains - you can get another 100whp with those easily