Most modern smartphones have a barometer built in. You can get a free app for getting the station pressure, and a good ballistics app is less than $10 (Ballistic will get the the pressure data from the phone barometer automatically).
I bought the Kestrel with wind, temp, and relative humidity (3500 maybe?). I use it and an iPhone ballistic app (Ballistic and/or Hornady 4DOF), and it gives me all the info I need.
If nothing else, I recommend getting a wind meter of some sort, just so you can practice the wind. I pull mine out when hiking, scouting, and target shooting, and use it to "calibrate" my ability to guess the wind using mirage, foliage, and the old Quigly dust sprinkle.