Cheap Fire Bowl Propane Conversion

[lifes_journey]

I picked up a large fire bowl (29" x 24") previously used for wood. I want to convert it to propane with lava rock. I researched round conversion kits and they start at $100 usd. Any cheaper ideas? Maybe using a barbecue H kit or making a star out of universal tubes. Another thought is to get a hold of a cheap second hand propane fire bowl like they sell everywhere now for camping and gut it. Thoughts?

Another related question...

Why do you not see many propane fire pits/bowls? Am I missing something here. I want this bowl for warmth and occasional cooking. Is it just because wood fire bowls are more natural?