Just to add in,...the Sony DSLRs are basically Minoltas and as far as I know they will fit Maxxum (what the Minolta 35mm AF line was called in North America) lenses.
I have the Canon EOS Rebel XS which translates as the 1000D in Europe. It's entry level but I like it. I got it on craigslist at a screaming deal, but the Camera retails for $500 including 18-55 lens.
I think the main difference that you'll find between entry level, mid range and pro DSLRs are amount of pixel count and sensor size. Mine being an entry level camera it is a 1:6 crop sensor and 10MPs,...the next levels up whatever they are (I'm not too familiar with the lineup) have more features/higher MPs ie: 15MPs and the biggest one is the EOS 5D mk II and it is a full frame sensor (same size as a 35mm) 21.1 MP and I was quoted a price of $3200 USD.

. (The 5D mk II is also an EF-S only camera which means it won't take EF lenses

)
Sensor Size and MPs really comes into play for enlargements. I've never tried to make any actual photos from my XS but the larger the sensor/higher the MPs the better quality and bigger the enlargement you can make. To be honest,...I think I can get decent 8x10s (maybe even larger) from my entry level camera.
Here are some recent shots that I've done with it.
A question. When shooting B&W I always had a yellow filter on my camera to help with contrast and bring out skies. Does that translate over to 1s and 0s as well?