This border-radius is fine:

<style>
.cost {
	text-align: center;
	background: orange;
	color: white;
	font-size: 24px;
	border-radius: 12px;
}
</style>
<div class="cost">$1,000</div>

But increasing the radius to, say, 30px, results in an unsightly protruding stroke. Chrome and other browsers do not have this behaviour. Any radius beyond a certain threshold is handled gracefully.

If I read the spec correctly, Prince should not be doing this.

Pulse Energy

Right, it looks like Prince should cap the maximum radius at half the width/height of the box. I'll add this to the roadmap.

We have fixed this in the current alpha version.

Great! Is everything on the roadmap marked DONE in that alpha?

Pulse Energy

Yep, should be.