There are plenty of RG+ commanders that could make use of the cost reduction on their activated abilities, even if you never pump up Agathas power
This textured-foil of Spider-Man printing is worth almost $500 , partly because it shows Spider-Man in a dynamic, lunging pose, sporting the hilarious yet still impactful Fantastic Four suit, complete with a paper bag instead of a mask
Available Products MTG Foundations contains most products you'd expect from a regular set plus the aforementioned new Beginner Box and Starter Collection
Given payoffs like Runaway Steam-Kin, Storm-Kiln Artist, and Young Pyromancer, you can have a lot of fun with this one
A lot of effects are simply not worth a card regardless of the cost
If your play group is avowedly casual, and intends always to be so, then it's fine to have a house rule to "play the card as printed"