I visit fairly often with investors looking at a certain vacation rental property to make an offer on.  I am not a realtor, so I cannot give advice as though I am one, but there are some guidelines that I have used personally over the years, with great success. Maybe these will help you, too!

You’ve found the property you like, and the numbers seem to work, but it’s more than you can afford or want to pay. Here is the Collin Hays method of buying the property at what you want to pay:

1. Don’t ask the seller what their best offer is. They’ve already priced the property. This puts both you and them in an uncomfortable situation, as you are inferring that they didn’t already price it fairly.
2. Don’t make a list of the flaws of the property and use that to try to talk the seller down. They know they ins and outs of their property, and you bad-mouthing the property isn’t going to going to endear you to the seller. If you want the seller to accept a lower offer, you can’t offend them.  
3. Consider the possibility that the property is already priced quite fairly. I have given asking price several times with no quibble, particularly if I really liked the property and the numbers worked well.  
4. If you really like the place but you feel that it is priced too high for your budget, instead of saying “it’s priced too high” and insulting the seller, simply say “I absolutely love your place; it is exactly what I want, and I’d really like to buy it. It’s just more than I can afford, and I don’t want to offend you with a low offer.” If the seller says, “Oh no, feel free to give us an offer”, then there is your invitation.  
5. Find out what the seller has invested in the property if you can. In many states, this is public information. You can find the most recent sales price for the property on the local tax records website or by doing a quick search on Zillow. If you are trying to buy a $ 1 million home, and they bought it 20 years ago for $250,000, it’s likely they have a whole lot more wiggle room – and less price sensitivity – than someone who paid $1.2 million for it last year. Of course, what they paid isn’t going to take into account the money they have spent on renovations or remodeling, which can be substantial.  
6. Finally, even with a substantial discount, the house may not be worth it. Do your due diligence and make sure the numbers work for you. It may be that it works quite well at the asking price.  It may be that the price needs to be substantially less for the numbers to work.  You do not owe the seller any explanation on this.  They already made their investment using their own reasoning; now it's your turn.

Happy Hunting!