First off, shipping is outrageous from China. To get a shipment in a week or so is $26 at the cheapest. Take the slow route for about $9 and it could take up to two months to get your order. Here's the ticket if you're in the U.S.: There's a U.S. reseller on eBay for E-Cig liquids. Type in "smoke juice" and his site will come up for you. The prices are higher than E-Cig, but not by all that much, and you'll save on shipping costs and possible HASSLES from Customs (believe me, I know HASSLES).
You'll find most parts for e-smoking products are interchangeable, leading us to believe there are only a few factories of little elves producing these things which are then sold by everyone else under a specific brand name. I'm sure you can find cartridges for your cig somewhere other than the expensive original source.
I use e-liquid all the time. Just got the sample pack of all flavors, and am most impressed. In the past, I'd used tobacco flavors. Now I find the others are more interesting, but flue-cured tobacco is still the best base liquid, IMO. My newest order is for numerous 4ml bottles (the smallest) in flavors I can mix - coffee, cream, vanilla, flue-cured, etc. See the post from our good doctor for recipes.
With the mini cig, BTW, I just let a drop slide down into the cartridge. Periodically, I'll remove the cartridge with a straightened paper clip, and soak it all around.
Final edit: I have the syringe but use it only for empty cores for the e-pipe I own. Those are BIG. For smaller cartridges, dripping to refill is fine. I ordered lots of cores, rather than cartridges, and save money that way. I own a cig, cigar and pipe.