The issue with tubes vs. chassis is that you pretty much need to have them picked up. Shipping tubes so they are not damaged will get pricey. I don't know what the collecting scene is like in Alabama and what your options are for getting them to folks.
I personally think tubes are as valuable if not more than the chassis (since you could technically recreate the chassis whereas the tube is pretty much impossible). Naturally, this varies depending on the condition of the tube (e.g. burn). If I was going to hoard monitors, I would hoard tubes first.
As for an actual $$ amount, the market will tell you if you post them on the high side and then come down until you get a buyer.