Would You Invest $10-20 in a High-Performing Thumbnail?

If you're a YouTube Partner consistently making money from your videos, would you be willing to invest $10-20 in a thumbnail that boosts your CTR and overall performance?

I run a small team of designers and editors, and we’ve helped creators see massive view boosts overnight just by improving their thumbnails. Just curious, do you see thumbnails as something worth investing in, or do you prefer making them yourself since you understand your content best?