Comparatives are wonderful words and I think they are really good tools for practical learning.
If I were shopping around for a sturdy, inexpensive cellphone case, and I saw some that were too expensive I might ask, "Do you have some others that are cheaper than these?" That's technically correct, but a bit unwieldy. It's nothing you'd really say in a conversational tone. Better to ask, "Got anything cheaper?"
If you were bargain-hunting in your native language, how would you say "Got anything cheaper?" ^_^