Bluetooth vs GSM

Hi,

I need consulting regarding what is a better way to send data. I want to send data from my vehicle to a server in a constant building (obviously), I'm lacking any information about sending data wireless so i need your advise.
What i was thinking to is this:

  1. Add a GSM shield and then send via cellular to the server.
  2. Connect to my phone via bluetooth and then through my data plan (which i don't know how to do yet) send the data back to the server

Which way is better in money wise and complexity wise??

Thanks in advance