I personally don't think you'll get more than $250k if you sold her. That is, if you listed at $300 (or $299), I bet you'd draw a $270ish offer almost immediately (negotiate, you net 250.) If you listed at $350 you might not draw any offers at all.
Yes, I know what's listed on YW. But most of those prices out there are "wishes", to be honest, which is why they're still on the market. There's one other repowered boat I saw immediately with 3196s asking 350k and he's gonna own it for a while.
The general rule of thumb for a bigger boat is that you either sell her within a couple of months of listing it or it will sit on the market for a year or more. Why? Because if you price it right someone will buy it immediately - if you try for the last fistfull of dollars then you need to find someone who really wants your particular boat and doesn't give a damn about the cost.
That can take a good long while.
The paradox here isn't that the boat isn't great. It is. Its that the bubble boat market is where the big money is going, and there are fewer and fewer people out there who appreciate the classic lines of a Hatt and who are willing to buy a 20 year old boat (even repowered) at a premium to the other boats in the series out there.
Repowers are never cost-effective. You can buy a 45C with the original engines in good condition for under $200k right now, which means sellers are taking $170-180 for those boats. A couple of those look pretty good for the money. Figure - at best - half the cost of the repower is recoverable, and you're probably in the ballpark of what you could actually get if you're willing to wait a year for it to sell. Take $20-25k less and you could sell it quickly. When you add in the insurance and other carrying costs to keep it for a year, plus the time value of the money, there's no argument for going for the last fistfull - at a market return $250,000 earns you $25k annually, so you're absolutely flushed economically if you price for the top of the market.