I am very familiar with Southwest's pricing structure, and in fact, in my experience, the tax NEVER backs out exactly.

Travelocity does not offer any discounts, unless they are running a promotion with a particular airline, which I have seen in the past. In fact, when I searched Travelocity, the fare posted for all airlines on that route was $77, not just Southwest's. I have also since learned that Expedia is offering all roundtrips for those late January travel dates at $77 as well. Don't know if Expedia books Southwest though.

The point is that Southwest's website is charging more for the same itinerary booked elsewhere. I've seen this happen with other airline websites vs. the travel agency websites, but until yesterday, never with Southwest.