The AK is not cheaper right now. Plus, for SHTF, you live in the US where AR parts are widely available in case you need replacements. The AK is obviously widely available as well but not even close to the aftermarket of the AR.

The AR vs AK debate is widely held by two groups who are emotionally charged. It's all about your choice tbh. They're both great weapons but the AR has a way wider availability of aftermarket parts.