VistaVapors.com will send you a 12mL bottle for only 1.99 shipping if you're a new customer.
ApolloEcigs.com is offering two 10mL bottles for 2.52 or so.
Both of these promotions have limited flavors to choose from but at least you can try out a couple different flavor profiles and find out if you're more into fruity flavors or dessert flavors, etc. Once you find out what kinds of flavors you like, you can pick up a sampler pack from most vendors where you get to select five or so flavors at a reduced price, kind of like a bulk rate for buying them all at once, to try and nail down a specific flavor that can become your ADV (all-day vape).