I wasn't an ASA Instructor but was a US Sailing Basic Instructor for many years. Best pay I ever got was about $12 an hour with the YMCA. However, because it was a basic it turned into being a talented baby sitter on many occasions.
When the Red Cross used to have sailing classes I was a certified Red Cross Sailing instructor teaching out of Pearl Harbor and that was a great deal of fun with no pay.
I used to teach sailing at a local Navy
club in San Diego to adults in keel
boats and it was a great deal more fun with 98% adults. Here in Hawaii
too I've taught keel
and basic courses for our local club. A lot more fun with mostly adults. But in both those cases it was volunteer too.
Although US Sailing might call themselves non-profit. They get a lot of money
for their instructional certification courses and charge an annual fee as well as a fee for recertification. They also encourage you to be a missionary for the US Sailing form of instruction which is very much the same as any other sailing curriculum.
Teaching sailing is fun. If you can find a local college or university that has a sailing program you might find a job which pays a bit more.