Suggest Motherboard for i7 9700k under 250$

For the very best motherboard that has been reviewed very highly, the Gigabyte Z390 Aorus Master is on sale for $259.99 at Newegg

https://www.newegg.com/Product/Product.aspx?Item=N82E16813145089&Description=gigabyte%20z390&cm_re=gigabyte_z390-_-13-145-089-_-Product

To save some money, the GIGABYTE Z390 AORUS PRO WIFI is also on sale with the near same 12+1 VRM as the Aorus Master above for $195.14

https://www.newegg.com/Product/Product.aspx?Item=N82E16813145091&Description=gigabyte%20z390&cm_re=gigabyte_z390-_-13-145-091-_-Product

Both these motherboards will handle the 9700K and push them to there best with plenty of features included..

To see a review on all the best Z390 boards by Buildzoid and GamersNexus, here you go:

https://www.youtube.com/watch?v=v5NDtS8za8g

If you plan to overclock, then also factor in good cooling...