The six-core Core i5-12490F is a special member of the Alder Lake lineup as it is sold exclusively in China. At the time of release, the price was approximately $260, but four months later, the price dropped to $207. As a result, the CPU is now a more attractive purchase than the same six-core Core i5-12400 with a suggested retail price of $200 (in the US).
The thing is that the Core i5-12490F is based on a large Alder Lake crystal with partially disabled cores, so it has more cache memory – 20 MB versus 18 MB, and frequencies – 3.0-4.6 GHz, which is higher than the frequencies Core i5-12400 and Core i5-12400F (2.5-4.4 GHz). Here, however, the price factor of the Core i5-12400F should be noted: the recommended retail price of this model is $180 (in the US). So if the cheaper Core i5-12490F definitely wins in terms of price-performance ratio for a regular Core i5-12400, then in comparison with the Core i5-12400F, everything is not so clear.