Ya that's where I got the Castrol Edge lol. It was by far the cheapest there!

I did mine at 4k... Discount had a deal buy 5 Qts of mobile 1 and get a free Mobile filter. You can't go wrong with them and it's hell of alot cheaper! I've always trusted Mobile 1....

Castrol oils
 

Many have used Castrol for years in their BMW's and Porsche's but Castrol makes many diffferent oils with different formulas. Many in the German family of cars use Castrol Gold which, is a very good oil and manufactured in Germany but can be found in the U.S. at many stores. It will say manufactured in Germany on the back and does or used to come in a gold container thus the "gold" label. It has performed well in oil analysis over the years and talked about on bobistheoilguy at great length. I have not used it but many I know do and that is the only Castrol that they will use. I am not familiar with Castrol Edge and would do some searches or look on bobistheoilguy. Any time an oil is much cheaper then something else would cause me to think why but many times oils are on promo sales and you can find good deals. Again, the info is out there it just takes time. Remember, compared to the price of our cars all oil and filters are very cheap insurance so look at the issue closely ..However, opinions are like...........