One other point going back to the original post - the whiting 29 that's come up in your racetrack search is a slow one. If you change your search to full history you'll see them all and that loads rate more like 0.67. Still not 88 or 930 territory, but a decent margin faster than your d28.
If I were in your situation I'd say that the answer to your fundamental question is that yes you're better to upgrade to a different boat than throw heaps of money at the d28. Contrary to what's been said above a y88 shouldn't cost double what scarlet does, and fleet street sold recently after being ad