Does it count if I've been hypnotized by my own doggies eyes?
We have two rescue dogs (and a rescue cat... and usually a foster or two underfoot. Maybe I'm the wrong one to ask?) Anyhow, our first dog is a golden retriever mix and was the dog that was going to be our family dog for our two young kids. He's an *awesome* dog that we were able to rescue as just a puppy and I love him to death.
A little over a year ago we started fostering. One of the fosters came into our home... and I realized I couldn't let him go. We had had a few other fosters but none of them got along with our family. With Jack, he almost seemed to fill a hole. Honestly keeping Max became a lot easier with Jack. He was no longer lonely and no longer had any separation anxiety because he had a buddy. They've really been great for each other. Oh and I should mention Jack is a 50lb mixed dog so about the same sizes you're looking at since Max is 75lbs.
Having said that, I would be very careful that both dogs are a good fit for you, for your family, and for each other. Both of our dogs are on the lazy size so even though they're pretty large they spend most of their time laying about. We also have a large fenced in yard they can run around in when the urge strikes. Our house is only about 1100sqft, but honestly it doesn't feel snug because the dogs seem to fit the house.
The past month we've had a foster dog that was a little sweet heart, but boy oh boy was she a ball of energy. Zoom! Zoom! Zoom! It was exhausting. And she was only 10lbs! That 10lb excitable dog fit our family a lot less than our 80lb behemoth who's currently sleeping with his head on my foot. Super-hyper dog was just adopted to a young man who loves her level of energy and thinks she's hilarious.
So I guess the point is, choosing a pet is a very, very weighed out decision based on what your family needs and wants are. I would never, ever encourage anyone to get a pet that doesn't fit in because frankly that's not good for either of you and can end in disaster. You are the only one who knows what that means though, and whether you think those dogs would be good fits for you and for each other.
As for costs, they are costly little things but I've never regretted a penny of the money that I've spent on the love a dog can give. There are no more forgiving, loyal creatures out there. They're not for everyone, but I know in our family they're more than worth the cost and the cost of a companion for them (and a bonus one for us) has also been more than worth it.