Indirectly, it could be much more. You can fire the rocket from a different location on Earth. Switching to a different orbital plane is expensive.
There are other benefits.
Launch windows are usually limited due to the physical location of the launch pad.
Launches are very often cancelled due to weather.
There may also be something to be gained regarding ice hazards. Cryogenic rockets that sit along the Florida coast collect ice from the air. This doomed a Space Shuttle. Getting up to dry air before the launch could be a way to avoid the ice formation.
first stage delta-v is: 303 s * 9.80665 m/s^2 * ln (10200 kg / 950 kg) = 7053.19 m/s
second stage delta-v is: 333 s * 9.80665 m/s^2 * ln (2300 kg / 250 kg) = 7247.06 m/s
LEO requires near 8600 m/s. So, the second stage is necessary for LEO starting from 0 m/s. The big unknowns are how much delta-v is lost to air resistance and due to the gravity of the earth (launch trajectory optimization). To calculate those would require numerical simulation, see https://space.stackexchange.com/questions/20848/how-to-deter.... Optimistically an air launch would occur at 40k' (12k metres) and 600mph (270 metres per second). The effect on the first stage only due to the imparted velocity reduces the delta-v to 6783.19 m/s or a reduction to a wet mass of 9314.03 kg (885.97 kg of fuel). 270 m/s / 7053 m/s = 0.0383.