I have about 40-50 # of hops that I've bought from a variety of sources (Farmhouse, RiteBrew, HopsShack, and most recently a S__t load (31#) in a group buy.
Since I don't know when I will be using what, I vacuum seal everything, and store them in a freezer. If they came vacuum sealed with a tight seal, I leave it as is. If it didn't come vacuum sealed, or it appears there is air within, I reseal.
I bought 11# of cascade, and for this I sealed in 2# increments. For hops that I have 2-3 pounds, I will usually seal in 1# increments and also have a couple 8 oz bags. The 6x10 sealer bags easily hold 8 ounces (but don't quite hold a pound). The 8x12 bags hold 2# nicely. I've also used rolls, and they are somewhat cheaper, but they require sealing both sides and measuring as to how big. I double seal each end. Storing the hops is an issue...actually the issue is more FINDING the particular variety I am looking for.
What hops you will use most depends on what styles of beer you brew. I like hoppy APA's and IPA's. Because of this, things like Cascade (relatively inexpensive), Centennial (hard to get now), Chinook (somewhat more expensive), Columbus (cheap and easy to get) , Simcoe (hard to find in quantity), Amarillo (hard to find in quantity). I also seem to use a lot of EKG (English Ales).
It is still possible to get hops at reasonable prices from retail establishments. For instance,
HopsShack has Columbus for $6.99/#, Cascade for $10.99/#, Brewers Gold for $8.19/#, Williamette for $6.99/#, Galena for $7.59/#, Nugget for $6.99/#.
FarmHouse Brewing has Centennial for $1.25/oz, Cascade for $0.90/oz, Chinook for $1.00/oz and a bunch of others.
RiteBrew has Cascade for $10.39/#, Centennial for $12.29/# (great price!), Chinook for $11.39/# (pretty darn good!) and a bunch of other stuff.
I've ordered from all three places with no issues at all. Given you will need to pay shipping, the key is to order a bunch of stuff as the shipping cost for 10 pounds isn't much different than for 1 pound!
Man, I wish I didn't look at RiteBrew, that Centennial and Chinook look tempting, and I don't have a lot of either (only a pound I think) in inventory.