Bama, you are happening to come across sellers who really don't want to sell at such prices in the market.
Any boat for sale that sits too long, is overpriced, end of story, same for house, car, bicycle at tag sale, you name it. Move on to next seller, you will find one who actually wants the boat gone.
You are under time pressure from the Admiral to purchase, you may not want to continue shopping this way - it is not good.
Have you tried your local and backup Grady dealers? They get a lot of brokered gradys to sell, and you don't have to deal with any owners directly BSing you. You will pay more but get what you want sooner I bet, since the Admiral is more time focused vs. getting the right boat at the right price. You don't want any regrets later.
As far as two strokes or 4 strokes, has nothing to do with fuel consumption, you are looking at a point in time when transitioning from non-DI 2 strokes to 4 strokes occurred, so the value of the boat weights heavily, I would say the value of the non-DI 2 strokes is at least 50% -75% less than F225s or HPDIs at that time, so the overall price shoild reflect it
Also, if you want 4 strokes, don't get non-DI two strokes unless you figure $35K for repowering, you don't want to hear the Admiral complaining why your boat smokes and others don't, and the only way to shut that up it is by blowing $35K more.
At this point in time, you may have exhausted everything available for sale, either extend your range or continue to monitor market for new sellers to arrive, there will be more, financial crisis continues in USA, may even be worsening, unemployment rate on LI continues to rise.