I have some rare skillbooks for sale.
Astronautic Engineering - 25 bil
Mobile Refinery Operations (even more rare than AE, removed back in 2004) - 35 bil
Mobile Factory Operations (the rarest of them all, only few exist) - 50 bil
Those skillbooks were long ago removed from the game. MRO and MFO can’t be sold through market. Skills don’t do anything except hanging in your skilltree and making that extra skill in your total that makes you special and separate from the crowd.
Mail me ingame please.