If, and it is a big if, that fare includes first class on all segments, it would be worth it to me. The problem is that UA (and others) have a tendency to call it "first" but only actually give you first for one or two segments. I'd look carefully to be sure that isn't actually first class from PDX to LAX and coach from LAX to BOG or something similar.

Normal markup from coach to first on international flights is usually much more than 25%.