As you can tell from the various opinion, I really think the shape of the baby and whether it's a boy or a girl plays a huge part in whether a diaper will leak or not. What works for one baby may not be the best for another. Just throwing that out.
As far as price goes, start to learn what the average price per diaper is. It doesn't matter how much a box costs because all boxes have different amounts in them. A box of size 3 at one store will have a different number of diapers as a box of size 3 at a different store for the same brand. Know that as sizes go up, the price per diaper goes up. So once you learn that on sale you can get size ones for say $.17 a diaper, when you check out a sale of a certain brand if you see it's $.15 per diaper then it's a good deal (just divide the cost of the box by the number of diapers). if you get on the mailing list Babies r us often has $5 coupons off huggies and pampers boxes and that ends up being a pretty good deal. Walmart sometimes gets in huge boxes of huggies and pampers that end up a low price per diaper. The total cost of the box may seem high but when there's 200 diapers in it it's a good deal. Once you know what diapers work for your baby or what brands you're interested in and you have a list of the best price per diaper that you've seen, you will be able to spot the deals when you see them.
Also, for some reason, kroger often puts diapers and also swim diapers on clearance in the clearance section. i have no idea why but i always see swim diapers on sale for $2 a package when the're normally about $8 a package. I carry my coupons with me and I can get a package for $.50 when I use my coupon. The often have unexpired formula on clearance too which I think is weird. Whenever I shop at kroger i check out the clearance section and stock up.
Also know that you can use both a store coupon AND a manufacturers coupon for the same product. So if you have a target coupon for huggies and a manufacturers coupon for huggies you can use them both on the same package.
For me, for some reason the softness of the diaper is important. i find pampers baby dry to be very soft and much cheaper than pampers cruisers and they seem to work as well. Although the tabs do seem to break easily on baby dry for some reason. The cheaper huggies to me are very rough so I don't like them. Luvs and babies r us brand seem rough too.
One last thing is with boys, you have to make sure you put the diaper on high in the front and make sure his youknowwhat is pointing down. Oftentimes leaks occur because it's too low in the front and it's pointing up and it leaks out the top. hth!!