After playing the game for a while and building up your stores save
the game.  Now quit the game and go into your current save game
directory and make a copy of the base.dat file.  Now boot the game
back up and sell everything you have (if you need money) or transfer
stores (not ships or personel) to other bases.  Now save the game
again and quit.  Next replace the base.dat file with a the copy of the
original that you made earlier.  Now when you go back to the game
you'll have all the money from the sales plus all the equipment you
sold.  And, if you transferred anything those items will arrive
shortly.  Continue the above procedure as often as you like.