oh yes, those grabage stainless steel machine made cheapo from ebay is a disgrace to swords making. they are only used for decoration because they are not designed to withstand any form of impact which can destory the blade. I highly doubt those swords have a nagako, and a genuine hamon. the overal tsuka is probably poorly/loosely fitted.
the ones on that particular website are collections from Japanese master swordsmiths who spend months making them. the blades are fully functional and made with unsurpassed quality, paying exceptional attention to every step of their making. the type of steel used and the very process of forging, heating and cooling of the blade determines the overall quality and value of the sword.
I'm a newb to swords, so maybe someone can explain it better for you people.