Aw, poor Jackie! I think of you guys a lot and wonder how ya'll are doing. I hate he's having issues.
He sounds just like Zmei right now. He absolutely does need to see a vet. His breathing issues won't get better on his own. He'll probably be prescribed oral ab's, and most likely some kind of Baytril/Doxy combo.
Nibbler is right in that it could be a few different things, though it's most likely a respiratory infection.
I can guesstimate what might be wrong with him, but I'm not an expert and certainly no replacement for a vet. Given Jackie's background I'd guess the odds are high that he is contracted a URI but is also infected with Myco. The vast majority of rats in the US have it, being infected at birth from their mother or close contact with other infected rats.
It is a chronic inflammatory infection of an organism that is highly contagious and constantly attacks the lungs and reproductive tracts of rats. Most of the time rats' immune systems cope well with it, but if their immune system is compromised for any number of reasons, it flares up into an active infection and can lead to pneumonia. Repeated flare ups increase scarring in the lungs (much like asthma for example). Flare ups increase as a rat ages and their immune system naturally becomes weaker.
Myco is one of the reasons ethical breeders focus on strong immune systems in their rats. Rats who have weaker immune systems from the get go are going to have more flare ups over their lifespan. As will rats kept in unsanitary or otherwise stressful conditions.
Of the seven rats I've owned, four are from a single line, and have had virtually no problems with myco flare ups. My two hairless pet store rats, with their grab bag of weak genetics have had several flare ups, especially Skinner. My poor Zmei, whose entire litter exposed a weak immunity and problems with respiratory illness, has stayed on AB's most of his life. Zmei and probably Skinner will very likely have a shorter life span than my other rats because of this. Some of Zmei's litter mates have succumbed already.
The best treatment against myco is preventative. Breed for strong immunity; keep a clean cage; avoid common respiratory triggers like dust, cleaning chemicals, pine/cedar bedding; feed rats healthy diets; keep stress as low as you can; practice good quarantine.
When you find the vet, explain your financial situation to him/her and ask what options you have. He may be able to work with you financially. For example, my vet, when I was dealing with financial issues allowed me to weigh my rat at home using a digital kitchen scale from Walmart so that I could give the weight in Grams, ensuring proper dosage. He then prescribed the ABs and I went and picked them up without having to make an appt. All I had to do was pay for the AB's. They can be expensive depending on what the vet charges and how big your rat is and long your rat is on them. I just payed $90 for a month's regimen for Zmei my big fat rat, but I think that may be on the higher end of the scale.
I've got my fingers crossed for you guys! Hugs you and all your sweet babies.
Myco Info:
http://www.rmca.org/Articles/myco.htm