If you've never heard of the brand and they're cheap, then they are most likely the lowest grade rotors possible, when we're usually only talking single-digit dollars difference to go with a name brand.
Brakes can cost more in the long run to go "too" cheap, get a medium grade brand from Rock Auto or if pinching every penny, keep an eye out for Amazon Warehouse deals on damaged-box rotors. It is common that rotors damage their boxes from shipping damage that doesn't damage the rotor itself. I've bought several warehouse deal rotors that were in perfect shape, not even breaking the plastic bags they were in.
Common brands to look for in budget grade include:
ACDelco, Raybestos, Bendix, Wagner, Bosch, and lastly Centric. However, sometimes on the amazon warehouse deals you can even get those brands' premium line rotor for no more cost than their budget line rotor. What you get with their budget line rotor is higher quality control, that rotors with more runout are less likely to get through their quality control.
These are just generalities. If forced to buy at this exact moment instead of waiting on a deal at amazon then you might find the best price at Rock Auto. Pads, you also get what you pay for to some extent. Either they wear out faster or they wear out your cheap rotors faster and make a mess on your wheels, either way needing a brake job done again sooner. If getting them from Rock Auto which also has good pad prices, try to get some shipping from the same warehouse as the rotors to avoid higher shipping fees.