Southwest points are a cash equivalent. Each point is always worth about 1.7 cents toward Wanna Get Away fares. So the cheapest way to fly would be to use Southwest points on cheap fares.

CapitalOne points generally work the same way. Usually a point is worth 1 cent.

The other programs are based on a fixed redemption model. The ticket will always be a certain number of points. Thus it's probably a waste on such a short/cheap hop. If 25k Delta miles could take you across the country, why waste them on a short flight?

Advice: Study how each program's points/miles actually work and make an Excel spreadsheet comparing how much each is worth in your particular scenario - take typical flights and compare point/mile cost in each program to cash cost.