I wouldn't spend the money. That's not a racing boat. Generally, a fin keel will make a boat point better than a wing keel. That being said, most non-racing hulls should be sailed cracked off the wind some, to sail faster. If you saw the polars, you'd see it's probably faster to sail to the windward mark that way, rather than trying to pinch as high as boats designed to go to windward. Also, as mentioned, a smooth, fair hull with hard paint, and new sails, preferably cut for racing, would do more for you. Since it's a cruising boat, getting rid of any extra weight like tableware, linens, extra anchors, etc. should help some. Also, a proper traveller and remotely adjustable jib fairleads could improve sail trim. Good foredeck work with spin hoists and takedowns, etc. Being able to sail the boat you have faster, and to its rating should be the goal, and then if you don't think that's good enough for your race circuit, they you should probably consider a boat that is racer/cruiser or full-on racing...
I work in a bike shop. I see triathletes come in all the time, who want to put aero bars on their regular road bike, just because they see faster racers with time trial bikes. I see guys who only ever ride on the flat bike trail with aero bars on regular road bikes, and I crush them, because they never train on hills. And just putting aero bars on a regular road bike does not fix the problems of body geometry the way a properly fitted time trial bike does. So, I think they could go a lot faster if they would train with the equipment they have. Like, they have 80% of improvement yet to do with better training, and shaving a few seconds through "aero improvements" isn't going to get them there. I feel as if a new keel on your boat might be just like this.