For those dates, the fares are:

DEC 10 PHX->ELP:
Business Select $173
Anytime (fully refundable) $143
Wanna Get Away $106

DEC 17 ELP->PHX
Business Select $173
Anytime (fully refundable) $143
Wanna Get Away $49

The difference between Business Select and Anytime is $30 for both directions, giving boarding priority, 0.25 extra RR credit, and an alcoholic drink.

Compared to Anytime fares, the cheaper Wanna Get Away fares are non-refundable (but fully reusable as credit to a future ticket purchase if cancelled), and require buying up to the Anytime fare to do a same day standby.

So the difference between the Business Select and Wanna Get Away tickets you are comparing is:

Full refundability
Same day standby without buying up
Boarding priority
0.25 RR credit
Alcoholic drink

Personally, I would not normally pay the Business Select or Anytime premium over a Wanna Get Away fare. But I can see some people being willing to pay the small premium for Business Select over Anytime when s/he would otherwise buy an Anytime fare (e.g. on short notice when Wanna Get Away fares are not offered).