P-key101

I have had a Peavy TKO 80 bass combo amp since the mid 90s (my first amp) and unfortunately it’s taking up too much room and is no longer used. Therefore I’m looking to sell it on, however I’ve no idea how much it’s worth and with the sentimental attachment I have with it, I want to ensure I get a good and fair price for it. I am hoping there are some of you out there who are able to give me a price I should be looking to get for it. Also with it’s age is it now deemed collectible or even vintage these days? Another question I have is where would be the best place to sell it or advertise it? Finally, if I require to send it to a buyer, with it’s very heavy weight how much should I be charging for shipment? I’m also based in the uk for pricing those giving potential pricing quotes. Thank you in advance for any help or advice given.