AGA Legacy is dual fuel only. Electric oven and gas(or propane) stovetop. Blue Star only makes all gas(or propane) ranges not dual fuel. Relative to 100 gallon propane tank the difference between 22k btu and 15btu or 7k btu is miniscule and irrelevant. You can always turn down the Super Nova burner down to 15k btu but you can't turn up the Legacy burner up to 22k btu. Nobody "NEEDS" a Bluestar nor an AGA Legacy. Our grandmonthers managed to feed our families on 8-10k btu burners. 22k BTU burners can be very useful for techniques other than stir-frying. Sautéing, searing, grilling, boiling large amounts of water, and quicker recover times. Dropping cold food into hot pans lowers the temperature of the oil and/or pan. Deep frying for example. If you have oil at ideal 350 degrees and you drop cold chicken the temp of the oil drops and you are no longer "deep frying " but paraboiling. Instead of crisping the exterior the oil is seeping deep into the chicken meat. Gross. Powerful 22k btu burners help you to quickly get back up to 350. In addition there is the differences in the evenness of heat between a traditional open burner and a sealed burner like the AGA Legacy. With sealed burners it will be hotter around the edges of the pan while open burners are a lot more even across the pan. Cheaper options? American Range Performer Series(an open burner range made in Southern California) 36" starts at $5k and Bluestar makes the RCS with max 15k btu burners. Cheaper you start looking at Mexican and Chinese made ranges like the Chinese NXR at $3200 for 36" propane model. The cheaper American made ranges begin at a much lower price point, in other words cheap stuff. This post was edited by deeageaux on Wed, Jul 3, 13 at 19:15

Buy it. If you rent it, you can't price shop and will pay higher prices for your propane. You may also pay an additional premium as a captive customer, since you won't be able to predict your usage very well. They should be able to run off of one tank. For backup, I would buy a 500 gallon tank. By law, they can only be filled to 80% of capacity, so a 500 gallon tank only holds 400 gallons of propane.

I hope the person takes my previous advice. The regulator is not the only limiting factor. The surface area of the gas in the tank is a limiting factor. The gas must "boil off" and become vapor prior to leaving the tank. A small surface area delivers less vapor than does a large area. Cooler temperatures also slow the transition from liquid to gas. So the propane vaporizes more slowly at the very times that demand is greatest. Propane dealers can determine the tank size needed for your application.

We are in the same situation (a 1,000 gal underground propane tank + the high price!). In any case, before deciding on an induction cooktop, we asked about hooking into this tank for a gas cooktop. That would have required running a line almost the length of our house. The company suggested getting a separate 50 gal tank, which would be cheaper than running the line. They said one fill would easily last for 6 months of heavy cooktop usage. Before we installed the underground tank, we had a 50 gal one for our gas fireplace, It sat on a concrete pad that was about 28" square (maybe 30"); the tank was about 24" (diameter) by about 40". Hope this helps. But Bee's advice is best: call your local company and see what they recommend.