I agree with much of what has been contributed here already. There are a few points I'd like to make.
I have three B&M shops near my house. One makes their own. One re-sells local e-juice. The third has a house brand (that they purchase) and also sells many popular brands; ie. MtBaker, Namber, Cosmic Fog, etc. These "national brands" are almost always pre-steeped. For example, the MtBaker I purchase locally has been made 4-8 weeks earlier (MtBaker dates their bottles). While I paid $10 ea for 15ml bottles, I could vape them immediately and avoid a 10 day to 4 week steeping process. While that's twice the cost of ordering directly from MtBaker, when you need juice NOW, it's a good alternative.
I've also learned that tasting juice (at the juice bar) in the cheap CE4 clearomizers and stock eGo batteries is not a good indication of what the juice tastes like or whether I'll like it. This third B&M keeps the bottles of juice they fill the clearos from on a shelf behind the bar. They allow veterans to drip in their own devices to taste. So I picked up a couple of bridgeless dripping attys ($5 ea.) to taste juice, whether at the B&M bar or my own steeping stash. This gives a much better idea of what the juice is ACTUALLY like and how lousy/good your clearos/tanks are working.
Lastly, in addition to sample packs, keep an eye out for eMerchants that run daily/weekly/holiday sales. Get on their mailing list. For instance: MtBaker just had a July 4th sale on their already inexpensive juices; several eMerchants had 10-20% off coupons, even their sample packs; killer-juice(dot)com has weekly sales (Thurs-Sun), offering, varyingly, 1 to 5 of their (all pre-steeped) flavors for $.99/15ml bottle. If I don't like the sample/sale juice, I simply pass it on to another vaper and have only lost a buck or two.
In the same vein, the local B&M was clearing out flavors that weren't moving well in their shop. I picked up three MtBaker flavors (MooJuice, BlueMoo & Ecto Cooler) @ 3 for $10 (pre-steeped!).
I've only been vaping for just over seven weeks and have been analog free for almost four. I'm still looking for ADVs (all-day-vapes). I don't have one yet. I am, however, constantly surprised by what I do like. So I taste practically anything I can. If it is reasonably highly customer-rated, and on sale, I'll try it. If it's in front of me, I'll try it. I've already saved $168+ in analog costs and have only spent $115-120 in vaping gear & juices. I'm already ahead of the game. If it eventually costs me three months worth of analogs to settle in to vaping, then so be it. I'll wind up saving $140+/month over analogs and feel much better for doing it!
Good Luck & Happy Vaping!
~Alden