I’d offer you £30 for a working lower case assembly, i.e. touchpad and it’s electronic components/cables as mine is playing up. Don’t necessarily need the keyboard. I’ve seen them for $50/60 on ebay.
I think people may be reluctant to buy a used HDD.
If you have a look on ebay it seems more profitable to split the parts down into small components, fan, microphone, ac input jack are the sorts of things people often need to replace.
Hope this helps.