This is not like buying a PC or a monitor. It's not so simple as "value for money" or "performance for money".
When you buy a DSLR, you're not just buying a camera but you are buying into a system (ie Canon system, Nikon system, Olympus system, etc). You are buying into the user interface, the lenses, the flashes, the accessories, the software, the file formats, the way the camera is designed, etc. So it's not just about which DSLR has better performance or value for money, but which system serves your needs best, which one has the least compromises for your particualr needs.
For instance, Nikon is regarded as having the best flash system, so if you do flash photography a lot, that will be an important factor in your consideration.
Once you buy into a system, it's hard to switch because they each have their own ways of doing things.
So do your research, there's tons of pages on the Net about what's good and bad about each system, then make your decision. Ask questions n forums only if you really can't find anything after googling, or if the answers you can find via Google are not good enough.