The "best" tool is the one you have when you need it. This applies to hammers, spatulas, pencils, and even cameras. If I decide I need to take a picture of something and the iPad is nearby, that's what I'll use. There are lots of better cameras, but sometimes they aren't nearby.
I love the ipad air. I recently stuck it into a crack in the ceiling to take a picture of a plumbing leak. Couldn't do that with a normal camera. Could have done it with an iphone if I had one. The ipad came out splashed with water and crumbly plaster, but that one picture saved me a couple of thousand dollars in unneccessary work because the leak was not where everyone thought it was. It made the plumber's and plasterer's jobs much faster and easier and saved me enough money to replace my iPad twice if I had to ... or maybe even buy an iphone. Pretty cool, right?
Then, I stuck the ipad inside a desk drawer and took a picture to see why the drawer would not open and close properly. The lock mechanism was bent. That saved me half a day of taking apart the wrong side of an antique desk to get to the bent parts.
My original ipad had no camera and it's the one thing I wished it did have. And, the ipad air camera takes better pictures than the 2 point and shoot cameras we own that have more pixels.
So, no, I would not buy a crippled, cheaper ipad.