Putting values on kit for re-sale

Someone living near me wants to sell her HiFi system (17" discrete units) since the death of her husband.

It's pretty ancient but in its heyday was a piece of kit that would have most slavering over it:

Arcam units (Alpha 8R amp, Alpha 8 Tuner, CD72 CD deck) plus Tannoy M20 speakers and Sony TC-188SD cassette deck and turntable - Thorens TD 160 super.

Finding sensible reserve prices wasn't too hard except for the Sony TC-188SD cassette deck and the turntable - Thorens TD 160 super.

I guess no one but a collector of oddities would be interested in the cassette deck so I guess that's worth little but please correct me if wrong.

However, I suspect reasonably serious money would be needed to procure the Thorens TD160 super. This turntable seems to be valued at anything from £300 to over £1000.

Does anyone know what would be a reasonable reserve to put on this last piece of kit before submitting it to ebay for example.....or is there another, better way for her to sell it? Any advice on the other kit's valuation would be welcome too, please. Thanks