I think PKJ has the best advice. That was sort of my oringinal plan. Buy 5 small bottles per week, until I got a large collection built up, or at least until I knew what my favorites were going to be. However, my first order contained a flavor that I think will stay with me forever. Mint Chocolate Chip from Totally Wicked. Now the questions I have to ask myself, do I want to stick with that, and not even try anything else? do I want to experiment with other vendors' versions of chocolate mint, since the TW stuff is pretty expensive? Maybe I'd just like plain mint, or menthol (Is there even a difference between mint and menthol?)
Another word of advice, these reviews are your friends. True, taste is subjective, and all that hooplah, but there is usually a general consensus about what vendors are good and not. For instance, Backwoods brew. I think I've read only one review of them having a "weak flavor". Otherwise, people are fighting for a chance to try his stuff, because he has to shut down shop to get his orders caught up. Another flavor, Boba's Bounty, seems to be the holy grail of e-liquid. On the flip side, if someone says a certain company's e-liquid is bad (not mentioning any names here, but i think the "creek" is contaminated), its probably safe to listen to them.