LIFO question question

Elliotbay

A major benefit of LIFO inventory costing method is that it lowers income taxes.

However, along with assumption in rising prices - are we also assuming that the selling price will remain constant (gross profit margin will decrease in this case). If not, then if we were to increase the selling price in equivalent to match the gross profit margin, the income tax would exactly be the same as if one were to use FIFO or avg costing.

Can someone please validate the above assumption.

Let me know if this is not clear and I will provide an example.

Thanks.