$700 seems a bit on the high side for an EGM. We are in a block of 9 units and have had a number of managers over the past few years (long story). They generally quote $250 to $300 for a GM, but this can depend on where it is held, if it is offsite you pay for hire of a room which is a waste. Our current strata manager offers one EGM for nothing. The manager should have suggested doing it by proxy anyway.
Perhaps you should have asked for an estimate of costs first.