For other uses, see Sun (disambiguation). The Sun is the star at the center of the Solar System. It is a nearly perfect sphere of hot plasma, with internal convective motion that generates a magnetic field via a dynamo process. It is by far the most important source of energy for life on Earth.
Buying and installing a customer-owned aboveground propane tank runs about $450-$1,000 for a 120- or 250-gallon tank and $800-$2,500 for a 500-gallon aboveground tank. Installing an underground tank can cost around $1,800-$3,000 for 500 gallons and $2,000-$3,500 or more for 1,000 gallons. A Wisconsin propane dealer charges $1,599 to install a typical 500-gallon aboveground tank and $2,995 for a 1,000-gallon underground tank.
If you exchange, you are giving the propane company 5 pounds of propane and paying for the complete exchange. You will likely pay more for the exchange, even if your tank is completely empty. An empty 20 lb tank will hold about 4.7 gallons of propane. That is $18.47 at $3.93 per gallon, which is the low quantity price (I just paid $3.44 per gallon when filling several tanks). The exchange is about the same price. Keep in mind this comparison is as if the exchange gives you a FULL tank.