Weber Q to propane tank

I have been looking for a solution also to wean myself off of the 16.4 oz bottles. Where I live they average 3.50 a bottle (at wallyworld) so I looked at the 5lb. refillable tank. $65.00 where a 20lb. tank is $35.00. I would love to get one of those composite tanks but at around $150.00 there is no way I can justify that expense. I looked back at how many 16.4 bottles I used so far during this camping season.....so far its been.... uh....4. Now depending on how much you go camping I guess you have to ask yourself is converting worth the expense compared to what you actually use. It just isn't worth it for me to do it so I will continue to look for the 16.4 bottles on sale and use them as I need them.