The OE evaporator core is more money because its going to fit right and work right. I specialize in air conditioning and have replaced tons of Dodge truck evaporator cores. At one point I was doing so many I could easily do 3 in one day. The aftermarket cores just dont fit in the box correctly which means you need to fill the gaps with foam and hope they seal. Chrysler used to carry a value line of evaporator cores in addition to some other parts which were aftermarket parts that they had validated. The v-line cores used to fit fine, didnt have any issues with them. Not sure if they are still available or not