those companies have pretty large markups... Regular bullion they're ok (like bars/rounds, not ASE bullion), but the premium on the ASE proofs is rather high. Actually, aside of the generic bullion I find them to be rather high on quite a bit.
Numismedia is my go to price guide for all US coins... I believe many of out members use it as there main guide as well (but I very well could be wrong), Its usually still a bit high, like most guides, but rather accurate compared to, say, the red book for example.
I like the completed eBay listings because they show what people are really paying, right now. Basically what the true "market" price is... Here and now.
My LCS actually has pretty good deals on ASE's as well (all types).. So you may want to try to check a store... Get rid of that shipping fee.