Absolutely +1
If he's not gotten any offers besides yours, at least you can open a dialogue.
You can discuss what you think it's actually worth, and why.
You can discuss what you can pay, and why.
Maybe it will happen.
Good, honest communication works well if he's truly interested in selling at a fair price.
Good, honest communication works well if you're truly interested in buying at a fair price.
If both of you end up satisfied, it's a fair price. If both of you end up dissatisfied, the same may be true.
At least you're communicating on it, and negotiations can center on value.
Other tactics, based on reasons of less integrity, don't work when both are focused on relative value.