i'm now trying to beat boss 75 and now the pulse pistol has WAY better dps per cost compared to the particle ball (with a constant gradient with the other in between weapons). the next major upgrade is currently priced at 65.9Q for PP and 75.2Q for PB, while the PP does 346T dps and the PB 20.2T dps.
i assume this is not indended as back when i first unlocked it, the PB was better than the PP dps/price (same for weapons in between).
 "Destination Kepler")
 "Time Clickers")
 "Deep Sleep")
 "Doodle God")
 "The Last Shelter")
 "Symphonic TD")
 "Continuity")
 "Bullet Heaven")