The belt tensioner bushings on my 03 Cooper S went bad so I figured I'd replace the whole unit instead of just the bushings. The price from Mini was $224, Way had one for $199 and then I stumbled across a Gates replacement on Amazon for $74 shipped. I figured it wouldn't hurt to order it and if the quality looked terrible to suck it up and spend some real money. The good news is it is identical to the stock unit, It actually is the same exact part. Only difference is some identifying marks have been machined off and new numbers stamped in. I installed it tonight and am happy to say it fit perfectly and my car no longer sounds like it will self destruct at any moment.

Here is the link to the amazon part I purchased-

 

I have 30k on my $80 Gates and it works fine. It is exactly the same.

Another great find for me was the Spal power steering fan for $70 at Advanced Sports Vehicle.

Good luck

 

Yep, it's the exact same as stock. There are many parts that are overcharged by vendors and especially dealers; a little searching like you did can save ALOT of money.