Small compressors and boosters are fine if you are filling guns and very small tanks but when you start using them to fill large tanks they are not going to last long and any money you thought you were going to save will be lost to repairs and replacement. And don’t believe advertisers who say their small compressors and boosters are fine for filling tanks. There are commercial grade boosters and compressors that can handle the job but the cost is high compared to the hobby grade equipment and in the end the commercial grade equipment will pay for its self where the hobby grade equipment is like throwing money away if you try to make them do what a commercial unit is capable of. And commercial equipment is strong enough to fill tanks for others if you want to recoop some of your investment. And if you ever decide to sell your commercial compressor they usually have a high resale value, not so with hobby units. This is my take but in the end it is your decision.