I think part of the issue here is we dont have a recirculating credit system. Lets sideline buying them for a min.
1. There are few ways to earn credits. If you take your credits and buy voodoo packs (I buy a min of 10 per week) those credits are gone from the game for ever. There should be missions or bounties in game to earn credits and increase the supply. Even if you argue that you can then sell voodoo for credits, the ones you used are gone, and this directly affects supply and demand in game.
2. You should have to work for your credits, and the market works exactly the way its supposed to. I know some think that that should be able to run 5 ships, and have unlimited voodoo to cast and millions rolling in, but thats not how the game works.
3. People arent spending RL money on credits like they used to so the supply is down and the market price is up. Maybe there should be some other things people can buy with RL cashola to pay the piper. Maybe MOW's, ship upgrades, specialties.. etc. I know the community has given a whole slew of ideas on what to do to increase the games playability.
5. Lastly, maybe people aside from Zeph just dont like sloops
I mean you can make one with common things found in your bathroom.
If you try to "fix" the credit system you also need to fix the reason people hoard credits, which is because there is no where to put their money late in the game when research is done, buildings are done, plantations are working and they have no where else to secure the millions that are rolling in after those with trustworthy banks are filled. I know there are a few who think people do it for ominous reasons, and from time to time that may be the case, who knows, but mostly its due to no new end game stuff.
Even I suggested a "gold sink" way to do expeditions to find better ships, better cannons, better armor, Gems, rare items, achievements .... crickets
Remember...
You can sheer a sheep many times, but only skin it once!