Hi Anon,
you seem to have no idea about arranger keyboards my friend so let me help you a little.
Tyros models are past models.
You can only find a used one far from the price you have posted above.
There 3 basic categories of models:
Psr E series
PSR-E463(61 keys)/ EW410(76 keys)
Pse S series (current models are called SX series)
PSR-S670 (2015) There are still new ones in stores
PSR-S770 (2015)
PSR-S970 (2015)
PSR-S775 (2018)
PSR-S975 (2018) There are still new ones in stores
PSR-SX900 (Aug 2019)
PSR-SX700 (Aug 2019)
Tyros series (now Genos)
Tyros (1 May 2002)
Tyros2 (21 June 2005)
Tyros3 (17 April 2008)
Tyros4 (16 June 2010)
Tyros5 (13 July 2013)
Genos (31 August 2017)
There also some other models too with styles like the PSR A 3000 which is for playing mostly ethnic music,DGX 660 mostly for piano players etc
You can search the prices in stores on Google for your country.