A good sailor puts time and money on his boat.
No doubt. But a smart person doesn't dump 3K into a 4K boat that won't be worth more than 4 or 5 when he's done with it
If I was in a position to buy a carbon stick, I'd put my 5.5 up for sale, and use that +the 3K, to buy a 17R.
Just makes more sense to get a newer boat, thats faster.
Of course, I'm not a Uni - master, so my opinion varies.
The reason I'm not selling my 5.5sl, is the fact that it is a perfect dual purpose boat. Sail uni when it's light or there is no crew, or put up the big chute with crew and do some distance stuff.