I've found (relatively) inexpensive, high-quality curtains on Wayfair and Amazon, I've had luck at Walmart too. Instead of hanging one panel, why not two contrasting colors, or a color and pattern?

so you may need to purchase additional panels. How do I hang curtains if I have low ceilings? If you don’t have enough space above your window frame to hang a rod, you can opt to hang curtains ...

Solid color panels are oftentimes the go-to ... consider some best design practices. To create drama, hang curtains close to ...