You should search to see what other people are offering and for how much as well as what their postage is.

A VHS is quite thick, so most likely will go as a parcel, however if you just send in a padded bag with no tracking, you will lose any claim/dispute opened against you. The ones I looked at appeared to be sent in a small tracked satchel for $9.30.

Assuming that they have all been used, you should put it in the description and there is probably a "condition" drop down to select when doing the listing/s.

Take photos of the item front and back, as well as the box/cover.