Another aspect to look at is how much are you getting for your money? I love ECBlend, purchased my first juice flavors from them. I like that you get a small quantity for a reasonable price; you are not stuck with 15 ml of a juice you don't like. Great for trying flavors. As I am starting out, I don't know what I like yet, so ECB is great for tasting. Now I have some flavors I enjoy, so trying different vendors, but I still prefer to purchase small quantities till I know I like the flavor. I use low nic, low pg, most companies samples don't give you options, perfectly understandable, but right now I have a very popular flavor, great reviews, 15 ml bottle. Not sure it is the flavor for me, but I bought the bottle, not a high nic, high pg sample.
So I guess it is all up to you, your budget and your tastes. READ REVIEWS!!! I am basing more purchases on actual reviews and now that I have tried a few highly recommended flavors and thought "meh", I am really reading the reviews. I am also seriously researching DIY, because I am a flavor junkie, I like strong flavors so with DIY I can control my nic, pg/vg and flavor strength. I am no chemist, but I think I can master the basics with all the help here on the forums
Good luck, don't get discouraged, just stay away from those stinky nasty things.