Comparing Blue Nymph to other generator creatures..
Name active-cost:generated-cost
N cost if creature was vanilla, X for skill based on difference of cost, -1 if duo
=cost
Goose 1:1
2 body, 3 for skill, -1 duo
=4
Pharaoh 2:2
4.5 body, 4.5 skill
=9
FFQ 2:3
3.5 body, 3.5 skill, -1 duo
=6
Blue 3:6
5.5 body, 2.5 skill
=8
Jack 1:1
3.5 body, 2.5 skill, -1 duo
=5
tl;dr Blue Nymph has the best active cost effectiveness at the lowest cost to body. Adding +2 to the generated base costs makes these numbers less outrageous. Additionally the overall cost of Blue Nymph being so low may be related to UG being overpriced by 0.5-1 quanta. Arguably the skill can have a duo bonus since UG requires
. But that's double dipping since UG's cost should already take duo bonus into account