It's not a high end watch, made with a generic Chinese movement and most likely made as a promotional gift. The back of your watch is askew. Maybe the battery was removed or replaced, but not done by a pro. I just notice those things.
So, somewhere between $30 and $40 based on those eBay prices. Maybe a little less because the tin box has some dings that might matter to someone. I'd split the difference and ask $35... maybe take $25 if it's offered. If it didn't say Plymouth, it's a $10 watch.
That watch looks pretty cool, especially with that unique Plymouth design. As far as value, it's tough to pinpoint without knowing more about the brand or model, but a watch in that condition (looks mint!) could hold some collectible appeal. Since it's never been used, it might fetch a decent price among enthusiasts. If you're looking to find out more, there are sites like best super clone rolex that focus on watch replicas and clones, and though it's a different niche, collectors there might have some insight on your watch's value or where to sell it.