what can reasonably be expected of a seller?

Let's get the obvious out of the way.  If the seller posts the item "as-is" & "untested" then that's that and you get what you get.  Right?  But if neither of these is indicated and the item is listed as practically new or unused or immaculate....  or has been in ideal storage for years, then is it perfectly reasonable to ask the seller about functionality, to request the seller test the item to confirm proper functioning?  If the price is really good, is it reasonable to ask about functionality?    I've had 2 situations lately where this has come up.   In the first instance, the seller was willing to accommodate and I did pay for the item and was awaiting confirmation that the item worked properly but was unexpectedly told that he sold to another who didn't need confirmation and my money was refunded.  And in the second instance, I asked the seller to connect the cdp he was selling to a system to confirm that if worked properly as it could be a decade old and had "probably" never been used.  He responded that he wasn't connecting it to anything and didn't have time to sit and play it and that it was already packed.   So, am I just being unreasonable and expecting to much?  What do you think is reasonable?  Thanks.