7.39 should be possible as part of the 10c price step, but how would you get 37.40 out of the system? You could do 37.00, 37.90, 37.95, or 37.99 via the "X." ones, and the first category would all end in X9.
Developers can go in 10c price steps from $0.29 to $9.99 (0.39, 0.49, 0.59, etc), or in 50c price steps from $0.49 to $49.99 (0.49, 0.99, 1.49, 1.99, etc), etc OR developers can use the 4 supported conventions for any price in those ranges, as long as you fit within the convention.
But you cannot start at a supported convention and then use the price steps.
