Texas has 8.25% but New Mexico is 5.125%
Sunland Park, NM (which is part of El Paso, TX metro are has an additional city+county tax of 2.125% so the taxes are the same as in Texas (the numbers may be slightly off, but the final tax rate is very close to Texas)
I had the same issue a couple of times. I had to order it online for store pick up and just wait for an employee to fulfill the order