If it's a cheap deal and you're willing to take the risk, try it, but there is a large chance of issues with the plant with 12 days of travel I would assume. That's 12 days in pitch black. Depending on how it is packed, the humidity and temperature could vary greatly from hour to hour. The plant will be tossed around during shipping and there is a chance of damaging it. Most heat packs won't last more than a few days. If it's an expensive plant, I personally wouldn't take the risk. I would look for somebody locally that is selling the same plant, or is selling a plant you like more. I'm a completely newbie, but I have lots of experience with ordering live things online.