Amplifier to pair with Parasound Hint

My speakers are refurbished Ohm Walsh 4’s driven by a Parasound Hint I bought 2 years ago to pair with a Rega 25 and Parasound tuner/cd components. Would improved sound quality from a separate amp be worth a modest investment? If so, what’s a reasonable option for a system unlikely to be upgraded to high-end equipment for the next decade?
I've asked Richard Schram in the past about adding an A21 to my PSound Hint and he thought the improvement would be just so so, as the Hint amp section is excellent as is.
An A21 is about $2K used and the new A21+ is about $3K, so I suspect you'd have to spend around $4K on an amp to hear big improvements sonically.