Not to talk you out of enriching our industry - but if you are doing this for economic reasons, you should put pencil to paper. Keeping two stoves going is a LOT harder than keeping one going. You will have to handle and haul pellets up to the stove area by the ton, and you will also have the associated dust and noise (don’t show this to the other 1/2).....
So let’s discuss cost and price - look at your gas bill and try to determine the price you pay for Natural gas - for use here, let me guess is is $1.75 per 100,000 BTU (therm) when all is taken into account. It is less in many areas of the country, but higher in a few.
Let me assume that your delivered pellet price is $235.00
Using the calculator at:
http://www.hearth.com/econtent/index.php/articles/fuel_cost_comparison_calculator/
and plugging those number is, I get that gas would be cost about 15% more, BTU for BTU.
In other words, it would cost 470 for two tons of pellets and perhaps 550 for the same amount of natural gas.
So, from a purely economic standpoint, you have to decide if the initial outlay, the additional work, the service, etc is worth the savings of $100 or less per year.
Again, not talking you out of it - just that your post indicated that $$$ was a lot of the driving force....
that said, let me make two suggestions:
1. You could put a direct vent gas stove there instead - you’d still have the fire, save money because it is space heat, and it would work from a thermostat or remote if you want. In addition, it will function when the power is out and you will have no noise.
2. If you do decide to go with pellets, consider a “multi-fuel” model which can burn corn, high ash pellets and other current or future biomass. Locking into a stove that only burns high grade pellets seems like it could be a mistake. One of our site sponsors specializes in these (plug) - you will find them on the products page (Magnum) - but a number of other makers are starting to design for high ash pellets and corn.
In terms of total installed price, the gas stove should be the same or less as the pellet stove.
Also, if I were that serious about replacing all my heat, I would consider central heating - even with pellets or corn! There are many models available. This way, there is only one unit to fuel, and the mess is kept out of the living area, etc.
As usual, the above is purely my opinion based on your post.