Strange behaviour when buying a new ship

[Fritz]

As I had mentioned in another thread, I've made a little OXP for a new player ship. Of course I had to buy it, and everything seemed to work, but I came across two issues.

I don't understand how Oolite calculates the value of my old ship, especially the value of the built in equipment. It doesn't go into the new ship, so it should be sold at market price (or let's say 50% of the market price because it is 2nd-hand). But this doesn't seem to be the case, and instead of this something very strange happens.

My almost perfectly equipped Cobra Mk III with a recent overhaul on a level-14 planet had a trade-in value of only 147000 Cr. The combined value of the equipment including 2 military lasers, shield boosters and military shield enhancement (!) should be around 80000 Cr. Since badly equipped Cobra Mk IIIs are sold for much more than 147000 Cr. the equipment obviously doesn't go into the trade-in value. So where does it go?

Before buying the new ship I had around 42000 Cr cash (without counting gold, platinum and gem stones). Adding the trade-in value gives an amount of 189000, so after buying my new ship for a test price of 180000 Cr, I should have left 9000 Cr on my account if the equipment value is ignored. Actually I still had more than 25000 Cr! That's 16000 more than expected but much less than the value of my equipment.

So most of the equipment was lost in the deal. But I noticed something strange some trips and saves later: The amount of gold, platinum and gem stones had been reduced by amounts of 122, 126 and 121. There weren't any containers involved, everything still fitted into the safe. The market value for this loss (at the station where I made the ship change) is about 16000 Cr, so it seems that the ship change triggered the selling, and the surplus money I mentioned doesn't have anything to to with the equipment.

This seems really weird. Is it a bug, or, if not, can it be logically explained somehow?

By the way, this behaviour has nothing to do with my OXP or the standard equipment on my new ship. I kept the save file of my last Cobra III trip and I could and can exactly reproduce the phenomenon when buying a standard Cobra Mk III.

[Lone_Wolf]

There is a maximum trade-in-value for your ship.
I'm not 100% certain, but think it's 75% of the total value .

Aside from that, there's the ship_trade_in_factor .
A maintenance overhaul increases that value, but not automatically to 100% .
The increase is linked to techlevel of the system where you do the maintenance.
Maintenance at TL 7 will bring the ship_trade_in_factor over the threshold where maintenance is offered (85 i think) , but not by much.

Stock Cobra III price is 150k , you added 80k equipment = 230k total .

75% of 230k = 172.5 k .

85 % of 172.5k = 146.625k , just below the 147k you got .

[Fritz]

That would explain the low trade-in value. I can imagine that the developers didn't want people to change ships all the time, so it was made very expensive.

But it doesn't explain what happened to my gold, platinum and gem stones! It really looks like a bug, but perhaps there is a different explanation.

[Alex]

That would explain the low trade-in value. I can imagine that the developers didn't want people to change ships all the time, so it was made very expensive.

Oh I don't know about that Fritz. I recon the opposite, I'm sure all the builders would preffer you to try as many different types as possible.
I find it better to keep a copy of the save files for all of them just before trade in too. Never know when you will feel like taking out an old favourite.
I've also had great resposes from builders to help me modifie their designs to what I want, no matter how silly the change may seem. Even had one laugh and say "why on earth!" But seemed happy to help anyway.
A few 100Ks C. Mmmm cheap. The first Super cobra to come out years ago cost me something like 1.6 million C. Way, Way over priced in my opinion, wasn't even really any better than the stock Mk III. Virtually everything else was under 300K. Back then there were no where near the veriety of ship available.

The same thing regards gems and precious metal happened to me the first time, since then I always sell them all before hand. I don't impulse but new ships.