All normal auctions - Christies, Bonhams etc etc - one is able to set whether there is a reserve or not.  Why is Ebay Au so different?

Sometimes I do not know what to ask for on an item and as example:

Georgian Glass  list at AU$50 with reserve of $150 (real price sort of) and I get one bid at 50 then I have lost out.  If someone bid up to AU$120 maybe I could Second Chance Offer.   It lets me know 'market value;' at time of auction. 

Going to US site - postage is different and could be confusing.