I am considering changeing Samson's diet , he is a mix black lab /cheasepeak bay retreiver he is 4 months a 2 days old at 43 pounds

... I have been feeding him a mix of Eukanuba's Large Puppy Formula + Lamb & Rice Puppy Formula.. he gets about 26.5 grams of protein . I have been considering switching to another food.. { I had plenty of other topics going on Doggroups.com but their server has been down for the last few days I need some info fast...} One of the best foods I've found is Blue Buffalo . it's very $$$ $42 for a 30lbs bag .. I'm thinking about Blue Buffalo , but I'm coming into ALOT of problems find a PetsMart location that sells their stuff , the closest is 473 miles away

... I am considering buying a large online bulk order of Blue Buffalo , but I need to know if dry dog food goes bad after 6 months or so????? Also to bypass the problem of haveing to buy my dogs food online is bulk orders .. what are some GOOD { price is NOT a issue , I love my Samson

} dog foods , there are no petsmarts only a Petco , Pet Star , and a Super Petz.. so my brands are limited to those that those places cover , unless I buy online , in which case I'll get the Blue Buffalo .... I want it to be non-corn based since it is not complety digested by dogs , and less than 26% protein. Samson is a BIG BOY , and I have read about plate disformation and hip dysplasa.. So I am very concerened about his diet , I watch his feeding very closely and I feed him 3 times a day 2 cups per meal..
So in closing with that thread
Any good/ bad things to say about Blue Buffalo?
Does dry dog food go bad?
Any other suggestions for a GREAT , repeat GREAT dog food , for a large breed puppy , 4 months old
Thanks For the Advice!!!
Here's some pics of Samson incase you're interested...
