How much is Guyver Manga Video Collection worth?
Here's an eBay auction that is selling the entire series on VHS with the items listed as "Good" condition. Description:


  Good: An item that has been used but is good condition. May have minor damage to jewel case or item cover, including scuffs, cracks, or scratches. The cover art and liner notes are included for a CD. VHS or DVD box is included. Video game instructions are included. No skipping on the CD or DVD, when played. No fuzzy or snowy frames on VHS tape, when played.


It's currently listed with a starting bid of £27.00.

Here's another eBay auction selling the entire set that's listed as "Like New", with this description:


  Like New: An item that looks like it has just been taken out of its shrink wrap. No visible wear, and the item is flawless and intact. 


It's currently listed with a starting bid of £25.00

There's a couple of other sellers selling an incomplete set for around $31 or £18.44 so it seems the going price is around the $40 to $45 USD range. Single VHS episodes seem to be asking for more than the entire collection (per VHS tape).