Paul, basketball is often reputed to be very expensive, on the whole, for a domestic player its not that expensive in relation to many other sports.
Compared to local AFL it generally is. Compared to hockey or soccer (maybe cricket) its really not.
Basketball has some economics of cost sharing which makes it much more expensive to deliver. Court hire is expensive, and often distributed between just 10-14 players - compare that to a soccer field, where 22-26 players share the cost of field hire (which is on an hourly basis much cheaper). Referees costs are similary shared between those 10-14 players whereas referees for a hockey game are again 22-26 players.
Uniforms requirements for basketball are comparitively cheap compared to many other sports - especially those where you simply just have to have protective equipment.
Insurance and registration, with the ridiculous exception of NSW, is generally much cheaper for basketball than for soccer, hockey, cricket etc. I can register for example in Country Vic for $30 for a full year, compared to soccer which is more like $75 for a season (half year).
My niece played a season of hockey - the cost was close to $400.00 all up - basketball at 6 bucks a week over 20 weeks was much cheaper - even counting insurance and registration.
But if you want the blowout, its court hire. I can hire a footy field for $1500.00 for a season (thats two nights a week and all day saturday). I can not get a basketball court for under $20 an hour, and some places I know get charged over $50.00 an hire.
Even at the better of these rates I only need 5 nights of basketball in a 3 court stadium and I am at $1500.00 bucks already. And the $1500 outdoor field hire is often giving me a pavillion which i run a bar and canteen in!