If you want a cheap flight from San Jose USA to Dallas, you've got one airlines to choose from.
You can use the filters on your search to see more flights and find cheaper rates – Dallas has more than one airport. So if you don't need to fly into Dallas/Fort Worth International Airport, it's worth checking your other options. The 2312 km flight usually takes about 3 hrs 25 mins.
If you're planning on going to Dallas during this time, you could take a look at other airport options. Or you could try to get a last-minute bargain.