It hurts!
I wanted to do the same and ended up purchasing a new tank. The real hurt is that you really don't get a new tank. Any tank is pulled from the pool and given to you while the "new" tank is added to the tank pool. For those of you not familiar with the "tank pool" process, a pool of tanks is available for use. When you want a refill, some places will exchange a full tank for the empty and send you on your way. Occasionally, they will refill your tank, but usually just exchange. The good side of this is that after yur initial purchase, you never have to pay for an inspection or tank test when the inspection period comes around.
