Today I found out why quintouple topedo tubes are so awfully expensive(which really bugged me for a long time). It's because the cost multiplier, which in the data is set to 5.5 for quint and 4.4 for quad launchers (which seems reasonable at first glance) and 1.15 for singles, then gets multiplied again by the number of tubes the launcher has, meaning a 5-tube deck launcher actually costs about 24 times that of a single. By setting it to approx. 1.2 for all the launchers, the cost now rises linearly with the number of tubes, so now I can finally use them in my financially restrictive campaigns.