A single RFL is 16 cost. I don't think the 2 cost difference is gonna be the deciding factor here.If we really want to go with high-maneuverability, it seems like the only obvious downside of 4 thrusters is that it looks a bit funny. There could be unanticipated downsides, but that's the fun of the quest. For those saying the cost savings is negligible, I think there's a decent chance it makes the difference between having say, 11 instead of 10 ships in the first batch.
Personally I'm fine with medium.
[X] Four Type-2 Thrusters (33 -> 42 Cost) [Very High Maneuverability]
[X] Two Type-3 Thrusters (33 -> 45.5 Cost) [Very High Manoeuvrability]