What's a reasonable amount of time for a place to sell if priced right?

For those of you who have been following SE for awhile, what's the quickest you've seen an apartment in Midtown be listed and then sold? I have cash and definitely want to buy but after going to several Open Houses, I think these apartments are way over priced. And I'm wondering if it's the real estate agents who represent the sellers who ask for the too high price so they can make more money or are the sellers just being unrealistic in this market...I'm sure it's a combination of both. Either way it's very frustrating and I'm beginning to realize that my 'dream apartment' in Manhattan is going to take much, much longer to find than I originally thought.