"Special" low pressure propane line?

Is there any reason why I can't just use regular 3/8" ID co2 line tubing attached to barbed fittings and fixed up with hose/oetker clamps? I am looking all over hell for various fittings and special $30 a pop gas line, but I'm wondering if there isn't an easier way to do this.

The best reasons are that hose rated for propane service is suitable for propane. Is hose rated for CO2 suitable for propane? Perhaps it is and perhaps it isn't. Does propane degrade the plastic in the tubing over time? I don't know and if you don't either then I would stick with the material that is certified for the job. One aspect of this that people often don't think of is that insurance companies are awfully clever at dodging payment of claims. If there is a kitchen fire from an electrical fault and they find a non compliant gas device in your garage they may be able to say that you violated the fine print in your policy and are, therefore, not covered.

Talk to your propane company or its competitors. Most do onsite hose assembly or can at least order the custom hose