seems pretty much fair to me, i mean there's no set-in-stone set price for marijuana on the street, so it's basicly between the seller/buyer how much is paid, and he is (especially if he lives more than 5 minute car ride away) doing you a huge favor by bringing it to your house... i mean it's not like he's trying to sell you 3 grams for 40$...

if i were you i wouldn't even bring it up to him... if you call him on it, he may decide to start ripping you off more, making you pick your own shit up, and charging you normal prices.... but don't take this post as 'take what your given and stfu' or anything, if it starts becoming less and less, or you feel your getting ripped off more and more (progressively more each time) then you might wanna say something like "hey man, what's up with all the shortage lately, i mean i knew your quarters weren't 7 grams and i was cool with that cuz you delivered it and whatnot..." or something along those lines..