You won't know seller motivation until you present your offer. There are 3 outcomes: seller may reject, accept or counter your offer.
It's hard to tell what offer would offend an owner but the best offers are ones that can be supported through hard facts. Prior to making an offer, it is our recommendation to preview the recently sold similar homes in your target location. This should provide you with a clear understanding of what your perameters should be while placing your offer.
However, the only way to find out what the seller is thinking is to make the offer. You never know what the seller is willing to take to make the deal. They will either flat out reject your offer or counter you and you will know where they stand. Good Luck