$150 for a complete CO2 system is on average depending on the components. I have heard people build them as low as $100 and as high as $500 (way to much). That is NOT low end at all, that is using quality parts that have proven themselves to me. I can get bubbles as low as 1 per 5 seconds too.
I (along with the others) am not saying you HAVE to switch to pressurized CO2. If you are happy with your results then there is no reason to change. However, I am merely stating that there ARE better options out there. I do not like however the statements you make which seem to be based solely on opinion and not fact.
Setting up gas CO2 is really simple and lasts without adjustment for 3-6 months (depending on setup and amount injected). I have had to rebuild my regulator once over 3 years (developed a leak - my fault) and that cost a whole $6.99 plus tax. Other than that, I do not touch CO2 other than refills every 3 months (I inject into 3 seperate tanks from 5lb tank). Sure I check the bubbles, determine amout of CO2 in the tank, but that is because I am anal.
I have anacharis that grows literally 12" per week (I throw seemingly pounds of plants away), asian ambulia that grow 8-12" per week and red rubin swords that double in size every two months. My slow growing clover doubles its coverage every 3 weeks or so. Further, every "professional" plant grower uses some sort of gas CO2 because it is easier and allows for a more available co2 source.
Just my $0.02
Aries