How much is a SLR? I hardly touched the camera.

The front is either copied or not to the point. The person who popularized your knowledge didn't even understand himself and misled others.

From your needs, you only need a camera that can shoot buildings, and you can shoot them when you go out. From these two points of view, I don't recommend SLR, because SLR is not the only synonym for high quality now, and it is very bulky, so it is really inconvenient to go out to play. Cut the crap and recommend several portable models with good image quality:

G 1x (relatively professional, 3800-4000), rx 100 (invincible portability, can be put in your pocket, 3600-3800 "), NEX-5R (super image quality, 4000-4200).

If you have advanced requirements for photography, or like the shiny shape of SLR, and you don't care about walking around with a few catties of melons hanging around your neck, you can consider 600d, 650d, d3 100, d5200 (the strongest entry-level SLR at present), 18-55 sets or 35 1.8 fixed focus.