IF you're looking for something cheap,,, check into your local farm coop and purchase some corn. I typically do this in late winter (after i'm all done hunting) and into the spring and summer. Like VoL said above, try the mineral lick too. Those are good to start in early spring. Find a good old, rotting tree stump and put some mineral salt, and regular salt on it. They will go crazy over it. PLUS... make sure you refresh the mineral lick area every 2-3 months.
...and on that day when my strength is failing, the end draws near and my times has come, still my soul will sing Your praise unending, ten thousand years and then forevermore!