NOW is a very reputable brand. But, the price can be more than others. Having said that, it is one of my preferred brands.
The Web site IHERB out of Southern California does stock it, and while their prices are good, sometimes you can find it cheaper from a few other vendors. But IHERB ships immediately, like usually the same day, and if you poke around you can usually find a $5 off first order coupon (new customers). Try retailmenot....
Coupon codes are posted by current customers who get a kickback for each new customer they bring in -- that's the only thing I do NOT like about IHERB. And NO I DON'T have a code for you to use. I just think that referral thing is a bit off-putting, but other than that, I like IHERB. They also offer a list of free samples and you can request one or two with each order. They have also been around for a long time and had a pretty good reference library online, where you can check out various issues.
Oh, Swanson Vitamins out of Nebraska sells NOW, I am almost positive. They also might have their own formula, which would probably be significantly cheaper. Swanson is a reputable retailer, but in the past couple of years, seems they have increased their prices a bit. But, their own label products are quite good if they have it...