I've taken up part of my back yard in order to put in a patio. I'll be using some some sort of paver stone to make an 8x10 patio with a couple of walkways. Lowe's recommends 4" of base using the 'patio base' they sell, followed by 1" of sand. Is the 4" absolutely necessary or could I get away with 2" or 3"? Also, is there a less expensive option than what is sold as a patio base? It's almost $4 a bag and one bag covers 6 sq ft. at 1" depth. That obviously gets very expensive. Thanks for any help.