Sportex back boxes on ebay worth the price?

Are the very expensive back box exhaust on eBay worth the high price?
The one that I guess is the most popular is obviously the most expensive at £190 and yes it's a direct fit and I'm probably saving £50 over buying one and getting it fitted...

I would say no, they won't add anything to performance, just loud chavvy noise.

'Late reply sorry'
I just want a bit more noise and the back end exhaust to look smarter.

Ok so I went to a place in Bolton and got an universal twin tail pipe back box and used a piece of flexible exhaust tubing to marry up to the pipe leading to the middle box.
She does sound a bit more fruity but definitely not obnoxious just looks alot better, the box was £50, a metre of flexible piping £10 and fitting at my mates garage was £30 as it needed a hanger welding on and there was some fettling to be done. May need new rubbers as they are old and allowing the middle pipe to hit the chassis.