Bearing in mind I unfortunately don't find them of much use due to only having about 5 metres of edging where I can actually use it regularly,
and the fact I have 2x SPFC ones in very good condition (each bought at the tip for $15 apiece) I probably don't value them as highly as many eastern states people would.
Have walked past at least half a dozen at the tip over the last few years - from some fairly dodgy series 80 models to quite reasonable later yellow PT models.
They are great at cutting retic ditches though, especially with the double width/edge blade.
When these were new, they cost more than a Victa Commando, so they were not a cheap bit of kit. They are perhaps more common over here due to the greater propensity of really fussy lawn owners over here. Even today, most contractors use cylinder mowers.
If you spend $600+ on an Alroh or SB back in the day, then you won't bat an eyelid over another 300 to keep your edges nice.
Thats my theory why they are more common over here
For one in really good condition, running with good paint and nothing needing doing (no grumbly bearings, good belt, etc) I would pay up to $170 - IF I really wanted one.
For the one in those photos, I wouldn't want to pay over $90. Would be nothing wrong with it as a regular knock around edger, but it just doesn't look like really great condition