A single +1/+1 counter probably won't win you the game like an OverrunOverrun would, but it will definitely deal out some damage to the table without you having to fear a crackback, and that's pretty darn good
Like most Pokmon cards, the value of Poliwrath depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (HSUnleashed)
With rare foil cards and exclusive club editions, these are particularly popular among younger collectors and international fans alike
If you prefer a more streamlined combo approach, you could up the count of tutors like Demonic Tutor and Vampiric Tutor
Mewtwo GX (Secret Rare, Shining Legends) Shining Legends was a small, limited-print special set released in the fall of 2017 that has consistently punched far above its weight class in terms of producing long-term collectible value and maintaining secondary market relevance