If I hadn't already bought the decorations for Carson's construction themed 2nd birthday party, it would be a no-brainer to go with a John Deere theme. The kid is addicted to "diggas" and "mo-mos" (diggers and mowers).
With the insane price of gas these days, consider this:
A trip to the grocery store, $6
A trip to the playground, $12
A trip to the zoo, $20
Riding around the yard over and over on Daddy's mower, priceless!