I love 30+ yr old houses, don't get me wrong. In fact, I have never looked at buying brand new houses for either investment or to live in. 300-360K sounds pretty cheap for Bayswater.. I am mainly looking at properties with land that are within walking distance to train station and the new shopping facilities, and they are around 400k mark. Given that Wantirna's house is around 500K now for a standard BV 3 bedroom houses, 400K in Bayswater is still relatively reasonable compared to Ringwood, Wantirna, etc. But when you compare the overall area to the other side of the town, suddenly it looks dearer.
I have absolutely nothing against Outer East or Outer South East, since I have lived in Wantirna South, Berwick, and now back to Wantirna, and they are all very nice places to live in. There are also visible evidences that the areas are getting gentrified big time. But CG wise, cheaper areas tend to run harder once the uptrend starts (after a long stagnant period), as was the case for Outer East. More importantly, cheaper properties will put less pressure on one's cashflow, which is very important for buy and holders.
Just my 2c worth.
I think more expensive areas tend to run harder. There's a limit on how far cheaper places can run because it's more proportional to a person's salaries and what an average person can afford. People can pay several millions of dollars in premium for blue-ribbon suburbs because they are akin to discretionary, consumer items.
Anyway the east is always more expensive than the west at the same distance due to stigma, infrastructure etc. The difference between Bayswater + HC is not big enough for HC to appreciate more steeply because that would mean the suburbs are on par and unless we say the west = the east in the long-run, I don't see it happenning.