[Griffins]

Buying unopened raw packs on ebay, getting them graded, and then trying to get your money back when they are rejected is a long shot. You may get a few thru, but I suspect you'll end up with worthless packs and no refund.
It takes at least 30 days if not more to get packs graded, and in a lot of cases the people selling raw packs are resealers who will not stand behind their product.
If you want to start an unopened collection go slow, buy legit, graded packs, and learn as much as you can about what to look for.
You'll pay a bit more buying from Steve Hart but you're virtually 100% certain of getting a legit pack.
Stick to "finds" that flood the market temporarily and drive down prices- '64 Topps Standup penny packs are the last such find, and prices are a fraction of what they were before the find and flooding of the market.
Cellos have proven to be especially problematic and extreme caution should be taken before the purchase of any, graded or not.
12 card grocery cellos from the '70's and Christmas rack packs are aftermarket creations and have no value.
A run of legit wax packs make for a great visual display, but a couple of bogus ones will really discourage you. Go slow, and don't be afraid to pay a bit more for peace of mind and good provenance. Nothing is more expensive than getting a deal that is too good to be true.
If you're buying modern I'd suggest full, sealed hobby boxes of Topps Heritage. Tough to go wrong there, especially if buying when they are issued.