I never bought empties, but at one time I had over 20 cases of bottles. Most of them were Sammies, some were Wachusetts, some were Mayflower, DFH, Magic Hat, Mad River, etc, etc. All the same long neck style 12 ouncers. When I switched to kegging I gave most of them away to folks just getting started in home brewing. Still have about 8 cases of cleaned/sanitized bottles (though for the life of me I can't say why )
Anyway, they are exactly the same bottles my LHBS sells for $15 a case.
I also have used the Sam Adams bottles, and a wide variety of others, but why only 2 cases? What size batch are you doing? On my first bottling experience, I didn't have enough bottles and poured beer down the drain. BOO. I usually get about 52 bottles out of my kits so maybe an extra sixer of bottles ready would be nice just in case.
I just cracked open a case of Guinness. They have a nice plastic label that I can cut right off (no adhesive or any of that garbage to worry about). And they got rid of the plastic thing inside the bottle. They are 11.2 oz instead of 12. I just bottled my first home-brew batch, and used only one of these bottles, but I'm assuming it will work fine.
Ive notice this concern of bottles , im planning on getting more bottles, theres a place downtown indy that has 24x12 oz bottles for $10. I am thinking of going down there and getting a few cases and most likely more stuff.