Is it intended behaviour to be able to spam distress beacons as long as you don't purchase Hull Repair? I got a lot of distance out of being able to buy weapon tuneups repeatedly as a good credit sink. Maybe purchases in the same "zone" apply a price penalty, that way you could kind of keep the behaviour while squeezing the player a little bit instead of making it virtually free. IE a distress beacon after a shop would have 10% more expensive prices, and another beacon would add a stacking 10% (or whatever value).