Type in the following codes during gameplay:

For extra cash :

Buy extra passenger cabins, go to bulletin board and accept passengers. Then, try to buy another ship. It will be refused, but the difference in price between your ship will be given to you - so try to buy a cheaper ship!

To warp further than possible with Hyberdrive:

Choose a system really far from you with Shift-cursor keys. You'll be indicated: nn tons required", "Out of range", "nn tons required". Now warp to where you really wanted to go, using same trick, and warp again.