Is there a way to set a custom increment or custom values on the slider bar?

My organization is using Qualtrics to host our new request form for some of our print materials, and the slider bar is the cleanest way to display the values they're able to order these materials in. Ideally the options would be 50, 100, 500, and 1000 with no other options, but even if I could just set a custom increment at 50 so that the numbers generated on the slider aren't as random that would be a big help. I've scoured the forums but I can't find an answer -- how can I set a custom value on the slider bar or at least set a custom increment?