If your going to buy a new BBQ just buy a natural gas one. The holes in the burners are larger for natural gas versus propane. Just remember that you can't use propane on the natural gas grill unless you switch out the burners.
If your going to stay at your place for awhile it is probably worth it. I myself have a natural gas grill and i use an adjustable regulator on it and run propane. Works very nice and only cost me $15 for the regulator,(got the grill for free)