Advantages/disadvantages of different roof membranes?

I saw an ad for Mernard's today with different roof membranes on sale.
.045 EPDM rubber membrane in a 10'x100' roll is $469.
.045 White premium reinforced membrane PVC/TPO hybrid 10'x100' is $1089. (solvent weld)
.045 TPO 10'x100' is $519
APP Torch down is $59.97 per 100 square feet, so it would be $599.70 for 1000 s.f.

I think I can buy 6 mil poly locally in a 20'x100' roll for $79.

What is the advantages/disadvantages of each? Which would you recommend for a Wofati/Oehler house?

Jeff H.

I am currently thinking of using one of the above mentioned thicker membranes as my first layer over the roof, put down my dry dirt, then use 6 mil poly for a second layer.

Jeff H.