Help ? I don't want to get ripped off

I'm trying to sell some audio equipment for my grandpa. I don't know enough about the equipment to really stand by an asking price. I have researched each of the items, but pricing for some seems random and prices for others is unavailable. I have found a place that will buy them, but I don't want to get ripped off. I understand they have to make a profit, but I don't want to get totally "taken". I have listed the items below. Any pricing help would be greatly appreciated.

LSR&D Leach Super Amp Model 101

Magnum FM Power Sleuth Model 105 FM

Nakamichi BX-300 Discrete Head Cassette Deck

Carver Asymmetrical Charge Coupled FM Detector Model TX-11

Xfinity RX-10 Speakers Professional Standard Series

KEF Speakers Model 101 Reference Series Type SP3161

Nakamichi ZX-7 Discrete Head Cassette Deck

Nakamichi 7AII Compact Disc Player

Conrad Johnson Pre Amp Model PV2AR

Yamaha Natural Sound Stereo Receiver RX-V670

Thank you!
A good way to get some idea of value is to go to Ebay and look at the items "completed listings" price. That way you will see what the item has sold for and what the item's price was that didn't sell. Obviously there is a wide variety in the pricing because condition, desirability and seller's reputation all come into play, as well as timing.

I would expect that a one time buyer, who will purchase everything, will offer significantly less money to buy the whole package than you could get by selling each item on your own, of course this would also require a lot more effort on your part. So you have to decide if it's worth the extra few hundred dollars you may make on the sales to do the homework and selling yourself, or if you just want to dump it all for the quick buck. Only you can make that decision.
What condition are the Kef 101's. I might be interested.
BTW I owned them over 30 years ago and they were $600 new!
You might want to look at the Bluebook values here on Agon. Most of the pieces you have are pretty rarely seen and/or sold here, but it might be a good start.

"Taken" is subjective if you believe that the value is only what the market will bear.

As a buyer, I generally want to pay < 50% of full retail value for components still in good condition.

Some that achieve classic status will retain much more value and in rare instances, even sell for more than they did when new.

If you assume that the used price for a $100 pair of speakers might be $50 plus shipping, the bad news is that a 3rd party will probably offer you about $25.

Whether or that is being "taken" (I always thought so) or worth it to you vs the aggravation of retailing, packaging and shipping audio equipment - well that is up to you.

On Google, you can also type "component name" (space) MSRP and usually find the retail price pretty quickly.

Best of luck