The quality is there for a basic, inexpensive factory made strap. That isn't my thing so I don't own any. Last Davidsen watch I got, I gave the two straps away. I couldn't sell them for $15 shipped each.
I think if you step up to a Hirsch strap or perhaps a Don strap, you will pay a little more but get a lot more. Again this is my opinion based on my preference.
After that, there is a whole world of custom straps out there. You can check the sales forum here, Paneristi, etc. One word of caution though: once you get started buying custom straps and nice buckles, you won't be able to stop and it gets quite expensive.
Now with respect to ostrich and shark, BOB is a good option because of price.