Thanks and respected hjames, those of us who have moderated a popular BB/Forum know it's pretty thankless work and we sometimes have to make decisions to put out sparks rather than wait for the fire.
I think that the 1280 is well loved, if you love it keep it, if you don't then sell it. As much as many here will claim that vintage audio is a great investment, ... it's not. You make money on the buy, if you bought it cheap then there's profit but holding on to it will likely only yield a slow appreciation of its value and inflation adjusted they haven't historically done that well.
If you want to know value of the 1280 then most of us will watch sold prices on evilbay, be sure to compare restored with restored, documented original with documented original, provenance with provenance, just like a collector car. A nice survivor is worth more to people like me who don't want to get into someone else's quality of work and knowledge, but to others it is just a piece that needs to be restored.
Also note that values tend to cycle a bit, are a bit seasonal (winter/summer weather, Christmas/post-Christmas, etc.) and will typically peak in late December, some of the best buying season is starting to taper off (typically) in the fall. Prices now are a bit higher than when everyone is playing outdoors.