It all depends. If you as a seller always price your items higher than market average, then yes, you should expect people to ask what are you really thinking. Some people on eBay have that precise strategy - maybe deliberately (why leave any money on the table?) or out of sheer lack of awareness (suddenly found their long lost Pokemon cards and think a Charmander is worth $5000). On the other hand, if you consistently have competitive pricing to like cards in other listings, then yes, absolutely ignore these messages, unless you are desperate to sell to pay rent or something like that. Not sure which camp you fall in - you know better.
From a buyer perspective, if you never ask, the answer is a 100% “no”. If you ask, it is either “yes”, or “no”, or"maybe". That second scenario is more interesting frankly … and has a lot more possibilities.