A lot of the products you find on a web-retailers site, they don't even have in stock, they just order them when the customer orders them, that is why there are delays.
i think that depends on the web-based retailer. most of them have indications of whether or not a product is in stock, and if it isn't, they send you an email advising of when it will be in, and whether you want to wait, and usually they will also waive shipping.
bikeroom really sounds like it's a hit or miss proposition.