With the TS-590SG being sold around 1.500 € by several vendors in Europe, you find more and more old TS-590S in magazines and online flea markets. Some sellers think, they can get as much as the former invoice price minus 15 % or so for their old TS-590S. Really, this is ridiculous.
Last known selling price for a brand-new TS-590S with ALC modification from an official Kenwood dealer was about 1.385 €. So you cannot call 1.200 € for an old TS-590S from 2011 without ALC modification. I mean, you can of course and if you find someone being dumb enough to spend as much money for an old buggy TRX, you’re a lucky devil.
Following you find adequate prices (IMHO) for used TS-590S in good to acceptable condition, with all accessories and boxed as new (updated December 2019) .. just for the record:
TS-590S with serial number B09xxxxx to BC3xxxxx (2010-2013) without Kenwood’s official ALC modification:
650 … 750 €
TS-590S with serial number B09xxxxx to BC3xxxxx (2010-2013) with Kenwood’s official ALC modification:
750 … 850 €
TS-590S with serial number B41xxxxx (2014):
850 … 950 €
You may raise these prices by 50 € for the SO-3 TCXO (see note below) and by another 50 € for the VGS-1 voice syntheziser unit.
Please be aware of the fact, that old units should be aligned according to the (updated) service manual, because they may have a faulty factory alignment. If you take everything into account, an old TS-590S without ALC modification and without alignment can never bring in more than 800 €.
Note: high accurate TCXO for the TS-590S are being sold on Ebay for less than 30 €. I had one of those and at least the frequency accuracy is pretty good. Unfortunately it has a lot of spurs and a really poor phase noise. Please read this article by Mark W7MLG. Mark developed a high performance TCXO board for the TS-590S(G) and sells them at cost price, which is less than half of the original SO-3 price.