I'm planning on building a pair of bookcase/hutches like these:

https://imgur.com/a/eCVZT

They will be painted, so I'm considering 3/4 birch plywood, something I've
never used before. A local lumber yard quoted me ~$75 per 4 x 8 sheet. Home
Depot has (what they call) Birch Plywood for ~$50.

I know that HD lumber typically sucks but I'm curious: What does the extra
$25 get me at the lumber yard?

P.S. Would 5/8" be good enough for the carcass with 3/4" for the shelves
and top of base?

Thanks!