Looking at ebay price, that looks reasonable but get it recapped and restored. Assuming it's in physically good condition? The AU-517 would be as good as the 717 but with less power. Still 65w is a lot and ample for most needs.
I got my 717 from skippy124 who did this restoration video back in 2013. You will see him active in auddiokarma. Having met him personally, he is a very nice person and one of the best in Sansui amps restoration, if not the best.
https://www.stereo.net.au/forums/topic/55836-another-sansui-au-717-restoration/
The last few nights, I'm amazed at the musicality of the 717 driving my LCD-2f. Quality bass that is deep and low. The lushness of midrange. It's a great tone. The tone controls and loudness switches are not gimmicks. They are actually fun to experiment with but generally I left them off. When I tried them, I couldn't help smiling.
Another picture of the insides of my 717. Skippy has completely overhaul it.