Pet store animals, especially rats, are frequently sick, which is why most websites recommend that you quarantine them. I would call around and try to find a vet that will take payments. Lab rats often do not have myco, or a good immune response to other respiratory infections because of the types of research they may be involved in.
Both ratties really need to see a vet immediately, as everyone mentioned.
We are as gods to the beasts of the fields. We order the time o' their birth and the time o' their death. Between times, we ha' a duty. - Terry Pratchett.
"Men have forgotten this truth", said the fox, "But you must not forget it. You become responsible, forever, for what you have tamed. - Antoine de Saint-Exupéry