Ok I flipped it and the looks are promising. I used the last batch of epoxy for a third round. I touched up almost all the bald spots and also re did the spots that came out shiny from glue that dried before I sanded it. I'll post some pics of the final produce in a couple hours when I'm happy it's dried off good.
Altogether I used 10 packs of epoxy at $11 each. 20lbs of sand at .27lb, 7 cans of foam $11 each(I could have done this with 4 no problem if I used the Great stuff brand throughout), $18 for egg crate. 30lbs of Base rock $45, $5 for salt. It was a little higher than my initial estimate of $220, it came out to just over $258.
Worth it when you consider I get a great background, that provides pleasing looks, and lots of space to mount corals, plus a fantastic addition of filtration!
Its also worth noting that I put the posxy in boiling water for about half the time, it cameout with the consistancy of honey at room temperature. This is just right for aplication. Not too runny, and just fine to apply fast, w/out bonding too rapidly.