As far as boat cost, why not split the cost with 3 or 4 others and as others have said buy an older boat. If you have a public lake nearby, buy a portable course, drop it in the lake, ski, pick it up and go home. My point is there are a number of options to participate and enjoy this wonderful sport, it just may take some effort and coordination to make it happen.
With respect to tournaments, for me it's a great environment to meet a lot of wonderful people. You can make it as serious and all business as you like or some combination and enjoy the environment. I believe the tournament environment is all about relationships and friendships. I remember 10 or so years ago, my friend and I decided to go to our first tournament, a local class C, and found a bunch of great people and lots of fun for kids and adults. I now take my grandson, he skied his first tournament this year at 7 years old, he had a great time, whether he was swimming, fishing, skiing or playing with the other kids.
My experience was and continues to be a great experience whether going to a class C or a record event. For me, offering to help, getting involved, meeting new people is a lot of fun. I hope those of you not involved give it a few tries and don't be bashful.