I have both the Retrospective 20 and 30. I use them for slightly different purposes now that I have both. I have a D700+grip, 24-70, 70-200, 16-35, and 24-120 and I select the lenses to bring based upon the shoot idea.
I started with the Retro 30. I found the Retro 30 is a great all-around bag. It holds the body+lens attached, and has space for 3 more larger lenses. It has the two pockets in the front to store the extra things. What I found, is this bag is not that deep so when I'm out shooting and want to stow my camera with the 70-200 attached, it doesn't really close well where the velcro will secure it and it bulges out.
So to make it easier to have the camera go in and out with the 70-200, I went out an got the 20 as it is a deeper bag. It holds the D700+grip+70-200 attached, plus two other large lenses inside. The cover closes nicely. It has the one large pocket in front which is huge. I like it for all the extra items or even an iPad, though that also fits in the zippered pocket on the back side.
So, if I want one camera bag to carry the maximum I want to bring, it would be the Retro 30. If wanted one bag that allowed me ease of in and out with whatever lens I have have on, I take the Retro 20.
I do find both bags heavy after several hours of walking around and touring, but they are mostly comfortable for up to 2 hours straight. They are great for where you want to walk and then stop and shoot for a while. For all day touring, I use a back-pack. As said before, they do not fit a tripod and have no straps to connect it to the outside. The Retro 30's extra space is nice if you also want to place a water bottle inside if you're out a long time.
To answer your question, is it worth it? Yes, think that is a fair price for a solid product.