Fruit infusing pitchers are pretty neat, but also kind of a niche product. The more unusual a product is in the marketplace, the harder it might be to save money on it. With that said, let us look at what the options are.
The lowest-priced thing you could do, as previously mentioned above, is to go with the Jokari Water Infuser. All you need is a pitcher -- and if you already own that, ba-da-boom!
The next-lowest-priced option online is this infusing pitcher from Bodum for under $20 at the time of this writing. Bodum makes quality kitchen products, and that model has gotten mostly positive reviews by shoppers on Amazon.
Offline, finding a good fruit infusion pitcher at a deep discount will usually depend upon patience. But if you have the time before you need your new pitcher, then wait for a sale from places like Bed, Bath & Beyond, Target, or Kohl's.
If you are a value-finder at Goodwill, from time-to-time they surely get infusers. This may not be an item you would normally find new there, but gently-used ones will go for a nice price when available.
I would not normally expect to find this type of pitcher at a yard sale, but if you are at one anyway, you may get lucky.
Finally, be sure to keep eBay in mind for savings on fruit infusion pitchers. I have included some eBay auctions below to help you find the right pitcher for you. (No need to thank me. j.k.)
May your new infuser pitcher infuse flavor in your life. Yes, I am cheesy. (I wonder what putting cheese into an infuser pitcher would do -- bad idea! Sorry.)