I recently saw two different camera questions on the world wide web. They were not posed to me personally--I was "party 'C'"--but I thought I might share and answer them here. Perhaps something I say will be helpful to someone.
The first question was, "Is it worth it to upgrade from the Nikon D5300 to the new Nikon D5500?" I mentioned last week that the Nikon D5500 is an upcoming brand-new DSLR that replaces the Nikon D5300. But the two cameras are basically identical.
The only differences worth noting between the D5500 and the D5300 are that the D5500 has a touch screen and no built-in GPS, while the D5300 has built-in GPS but no touch screen. The MSRP on the D5500 is a hundred bucks higher, too--that's worth stating.
Suppose you bought a car, say a 2014 Honda Accord with whatever the most common trim level is, and you've been driving it around for a year. Now suppose that the 2015 Accord is out (and it is basically identical to the 2014 model) and with that same trim level you get a sunroof included but the heated seats are not. Would you trade in your still-pretty-darn-new car for the 2015?
If you have money to throw around and if a sunroof is that important to you, then why not? But since you are buying Honda Accords, you are not likely independently wealthy. So it would be a waste of money to do that.
It's the same thing with cameras. It's a waste of money to "upgrade" from the D5300 to the D5500. Heck, the D3300 gives you the same image quality for even less. As far as image quality is concerned, the D5500 isn't even an upgrade over the "entry-level" model. Nikon wants to give you G.A.S. (Gear Acquisition Syndrome) by making you think unimportant extras are essential.
The second question was, "Is it smarter to spend $150 on a body-only Canon EOS 20D, or buy a new DSLR?" The Canon EOS 20D is a 10+ year old DSLR with an 8 megapixel APS-C sized sensor. When it was new it was considered a pretty decent camera.
Digital technology changes quickly, and DSLRs have been improving in every way. They are smaller, lighter, faster, and with better image quality. 10-year-old digital technology is practically Stone Age.
With that said, cameras don't make photographs, photographers do. Either you can or you cannot create good images. If you can create good images, you'll be able to do so with the 10+ year old 20D. If you cannot, not even a new camera will help. Photographic vision matters, equipment does not.
Perhaps the question is one of value. So you spend $150 on the 20D. You'll have to get a lens, perhaps a cheap 18-55mm zoom for $100, and you'll have to get the sensor cleaned (because I'm sure it needs to be cleaned) for $50. Now you've spent $300. If you shop around, you can typically find a Nikon D3200 DSLR with a lens for under $400. For less than $100 more, you can get a camera that is superior in pretty much every single way, and it should have a significantly longer lifespan for you (since it is brand new and not over 10-years-old).