I make a pretty basic rub of white sugar, brown sugar, salt, paprika, black pepper, garlic powder and onion powder.
I just did the math using the online prices from a local grocery store and some online spice dealers. I could probably make it a little cheaper, but I came out to $3 per pound.
Unless you are just using brown sugar and salt for a rub I don't see how you could get it down to $2 per lb. Maybe if you buy ingredients by the pallet.
Silver UDS with weber lid, UDS #2 black with a weber lid, 1995 Treager pellet grill, 22.5 Weber