However or wherever they do it the fact remains that the delta labor cost for filling a larger bottle is small (or 0) relative to that for the smaller ones so that the labor cost per pound is less for the larger bottles/tanks.
You don't need to remove the valve – there is a hose and a converter fitting that fits on the sodastream.To answer your question, it is possible, but I think you would need to remove the valve to do it, and that can be dangerous itself depending on your skill and knowledge of compressed gas cylinders. You would need to measure (in weight) the dry ice, and not exceed the bottle rating.
That said, you should be able to find a used 5 or 10 lb bottle on craigslist for around $50... more if it includes a regulator.
Take that puppy to your nearest welding shop and exchange it for a new, filled tank (doesn't matter if it's out of date as long as it's NOT a rented tank) for exchange.
I pay $11 for each 5 lb exchange, and the tanks I get look brand new. I understand it's only $20 or so to upgrade from a 5 to 10 lb., and the fills are only a couple dollars more.
Enter your email address to join: