I am not doing a rain head showerhead. Just a regular head (yet to be determined!) but I have noticed prices for the shower arms anywhere from 6.00 at Home Depot to 48.00 plus. WHAT is the difference? Is there a certain type I should be looking for? I need chrome....Not sure what style/size I should be looking for on a shower arm but am assuming the regular 8 inch would suffice but why such a price swing and is the more expensive worth it? thanks! melissa