Wouldn't be hard for a 300k house. Especially if it's painted, assuming you only include the boxes, doors and drawers. Though in this area a 300k house is a trailer, a foreclosure or a knock down/scrape off in a bad neighborhood.
I'm having a hard time with $300/ft. Even the amish cabinet makers in rural PA are $600/ft for custom built.
Semi custom here in Northern Virginia is 1300+/ft