As the old saying goes, "If it seems too good to be true, it probably isn't true." One gold and one silver eagle both MS 70 for $138.95? http://www.coinadventures.com/html/MS70-Gold-and-a-MS70-Silver-Eagle-Over-Stocked-Sale.html $5000.00 worth of slabbed coins for $69.95? http://www.coinadventures.com/html/Lot-of-$5000.00-worth-of-Trends-in-Certified-Coins.html I googled the contact address and a few people had complaints on this seller, aparently he is also on e-bay.
You are assuming that both are 1 ounce. The silver eagle is 1 ounce. But the gold eagle is 1/10oz. Notice that the seller does not say what the size of the gold is.