If travelling for work isnt an issue maybe try the mornington peninsula, dromana, safety beach, rosebud, mornington, there all nice suburbs, no idea on price tho, only part worth looking at around frankston is frankston south, i think thats fairly expensive though (mt eliza and mt martha are also good but left them out since they are the rich areas), you mentioned not being able to find places under 200k, if thats your budget then frankston north is the only suburb you will be able afford, which not only is where i live but is also the worst part of frankston, i think i picked a good street though, apart from the odd domestic every few weeks its pretty quiet in my street.
The suburbs i have mentioned are all in the south eastern suburbs along the edge of the bay, probably other good area's as well but i have lived along here most of my life abd its the area's i know the best.
From my experience the only suburb i would say NOT to live in is narre warren, i had bad neighbours and its an absolute bitch to get in and out in peak hour, there are pretty much 2 roads and in peak hour they are chockers.