There's no cheaper alternative with even similar quality. I tried the Universal brand, figured they're both hogs hair and the quality of hogs shouldn't vary, but the Universal lasted less than half as long. They started shedding bristles almost immediately and what didn't just fall out wore down very quickly. I also had issues with the steel nut pulling out of the plastic backing. I've even seen quality control issues where they forgot to put in the screws that hold the refill in, customers are scrubbing away and the brush falls out and they put a dent in their hood.
I prefer the standard length Erie - I tried the next longer ones once but they didn't last any longer. I replace them when the length looks shorter in the center so I basically just wasted money on the longer bristles.