I'll admit that I didn't read all the replies.. just a few.. but I totally don't understand what you are saying.. your logic is flawed.
You will need some kind of diapers.. a dozen diapers a day for a newborn and at about the same number of wipes. So, small disposable diapers and wipes will cost you, even with the cheap ones, at least $70 a month. At least, that's what it costed us and we used store brand for the first month of my dd's life. For three months, that's $210 or more (I can't even begin to tell you how many diapers we threw away that she peed or pooped in before we even got it taped shut and that's on top of the dozen legitimate diapers getting worn for an hour). I don't know what size your baby will be, but my daughter work infant prefolds and small wraps for nearly five months... so, that would be $350 in disposables.
But, for less than $80, you can get a nb basic pacakge from natrualbabies.com that has 3 dozen prefolds and six wraps, add a couple of snappis to that and pay for shipping. I just don't get how $80 is too much but spending $200-$350 on disposables for the same stage is even comparable. Yeah.. the $80 has to be up front, but if you have even a month before the baby is born, you can come up with that because you'll have to for disposables whe the baby is here anyway.
And, you can turn around and sell your $80 worth of diapers when the baby outgrows them for probably $60. So, your overall diapering cost for that stage would be $20.
if you can't afford to put cloth on your child, there's no way you can afford to put disposables on him or her either. Unless you are VERY good at elimination communication, you have to put one kind of diaper or another on your child and it doesn't make sense that you would choose disposables over cloth based on price.
I also don't get how not spending $200 up front is going to keep you at home for an additional 4.5 months? Am I just totally cloudy headed today and not understanding what you are saying? (quite possible *L*)