$5000 is what it costs to design, manufacture, and market. I doubt there is very much margin to mess with. They have a big investment to recover.
By comparison a set of full carbon Mach 2 foils without tiller, wand and linkages cost about $A6700. They have been available for some time but AFIK no one has tried to put them on anything but a moth. So maybe all the (non Moth) internet foil fanatics do not really sail at all.
This is the mistake with a market like the Laser. it makes sense in traditional dinghy markets where your appeal is raher limited so you have to start amortizing design and production costs right away. In other words, its essentially custom production - like a custom built house or custom built software.
But OTOH, if you are expecting a mass market appeal, you look only to recoup your production costs and an ROI on the production costs. Your desiign costs are amortized out over the full production run. So even if they were say $100k, over a production run of 10,000 units that works out to be $10/unit. Pittance.
And your tooling costs - basically you assume you will run your tool until it fails and needs replacing. These are AL foils - your amortized per unit costs are arouund $3-$5 per unit for the mold
So assuming a production run of say 10,000 units (that's 5% market penetration of all boats sold) If you sold them for $200 above cost of mfg you would generate $2 million in revenue above direct costs. Even if that's over 5 years that's still $400,000 per year of income, you can easily eat $100k of dev costs in that.
So figure that your stamping costs you $100/unit. Assembly maybe another $100 and miscellaneouus parts around $200 - and you have 3 components - thats a very rough SWAG cost of mfg of $600. $200 margin - is $800.
Given that a laser SAIL is $600.... you up that to $950+ shipping. And you really get a huge volume.
Now there is a gotcha in this. You cannot bootstrap this. you need an investor. and that investor is going to take 50% of your profits