I'm a pet photographer, so have a little experience here
FWIW, I DO give low-res digital files to my clients so they can post them on FB, have them on their phone, etc. Those are included in my session fee, actual prints are not. I'm considering changing that soon and only offering low-res files to go along with any prints they purchase (ex. They buy an 8x10, they get a low-res file of that image along with it). These files are not printable (I mean, I guess you could, but they'd look bad) and have my logo on them. I'm of the mentality that it's a "digital age", so I want to give my clients something they can share online, but I absolutely refuse to sell my full-res digital files. No way.
When you sell a full-res file, you're basically throwing any profit you might make down the toilet. That's why the good photographers who do sell them (note I said good, lots of "photographers" will include all digital files from the session, drives me nuts) charge a very high amount for them. When you have a full res file, you can go make any type/size of print you want from it, in theory.
I think for a $1000 session, the photographer you're using should be including some low-res files along with it. JMO though. Everyone is different.