Dell does actually sell Pentium machines with ECC support, like the smaller Poweredge servers such as T140. They've done this for a while, I personally run T20

Dell does actually sell Pentium machines with ECC support, like the smaller Poweredge servers such as T140. They've done this for a while, I personally run T20 with ECC and G3220 (sold like this by Dell). They do occasionally remove some features like IPMI from those cheaper processor options, but the ECC support stays.