Moved to lens forum.
Without knowing what you have, a lot of the older Pentax lenses are very good. Of course if you are not going to use them, by all means sell them. Make a note of the details of all your lenses and then have a look through the Marketplace forum to see what things are being sold for.
If you want, you can send me the list via PM before putting them up for sale and I'll tell you which ones I want.
The same goes for your old cameras as well, if you aren't going to use them, someone will.
Welcome to the forum BTW.