Should we foster her?

[Karen]

1.) I know that Saints can physically handle living outdoors, but since they are big mushes could a Saint used to being inside emotionally handle being kept outdoors?

No, as she's a "spoiled princess," she'd be emotionally devastated being away from the people all day. They are completely and utterly "people dogs" and want to be near their humans - ours would lie in a doorway if necessary, to be able to see as many of her people as possible. And she'll be missing her "children" as well.

2.) On the subject of being outside, the Saint would be kenneled and I'm not going to be happy with anything smaller than a 10'x20' kennel. (A 20'x20' kennel would be even better.) However, to purchase that size of a kennel brand new would be....very expensive. But on the other hand, you can get a deer fence that is 7.5'x100' for $300. That right there is a 25'x25' kennel.
Would deer fencing be able to hold a Saint? Or would I be better off finding multiple used kennels for cheap and linking them together?

"Deer fencing" from what I have seen online would not hold a determined Saint Bernard. Never mind an energetic 2-year-old one. If she had to walk through it to get somewhere, she likely would without even slowing down much, that massive bulk is good for such things.

3.) Another question that my mind is asking is, "What about expenses?" Tim is having financial problems at the moment and he may not be willing to pay for the dog's care. I think he should at least pay for the food and any vet bills that may arise, we can take care of the rest, but my mom is very antsy about putting too much pressure on him. Does having him pay for food and any vet bills sound unreasonable? Since Blackie and Rose together eat about 6 cups of food a day and we spend about $40 on dog food every month...a Saint's food intake would be about that same amount, correct?

4 cups of food a day might be about right, now that she's full grown. The females are a bit smaller than the males.

Because of Tim's unreliability, my mom is worried that after we've had the Saint for almost a year that when he comes back he won't want it back. After keeping it for seven months I'm not sure we'll want to give it up, but if we don't, we could always place it in a new home. Does this sound okay, or no?

If we don't end up taking the Saint in it will probably end up in a less than desirable situation - a shelter or just given away on a whim.

What do you all think? My mom is trying to decide for herself, but she values my opinion as well as you guys', even though she doesn't know any of you.

She - the Saint - would be better off with a rescue group and getting adopted out somewhere, in my humble opinion, if there's even a chance he wouldn't want her back.

Sorry I don't have better news for you, but I wouldn't want this Princess Saint to be miserable, and I am sure you don't want that, either.