It sounds like your GM is using a (very slight) variant of the AP system in RoCo. IV, the only difference being the initiative roll (none in the AP system). Otherwise, if your GM is always using the minimum AP cost rather than the normal rule of AP reduction due to stats (which is, I admit, rather cumbersome), an attack with a battle axe would cost 29 APs (close to the 30 you mentioned) and since a class I spell has an AP of 10 and a dagger an AP of 15, it fits with your "in the 30 it will now take me to swing at the next bandit, our cleric has time to cast 3 spells, the bandit has been hit twice by the rougue (sic.)" sentence.
Oh, and 30 APs is the cost of a 3/4 RM movement rate, so it allowed the bandit to "run to the exit of the cavern."
To be honest, the system is quite good, as it allows small, fast weapons to be, indeed, swung more often so one has the tactic to use them or slow but powerful weapons but it has the problem of having not been developed enough to include all kinds of manoeuvres and weapons.
Be afraid (very afraid!) of instantaneous spells really being instantaneous though, with their 1 AP cost!!
