The only time I've ever used P2W amplifiers I was running through the Villain Patron Arcs through Ouroboros. I wanted to get through the repetitive arcs as quickly as possible, so I set the difficulty to -1x1, no bosses, no AVs and bought amplifiers, created base temps, snagged a bunch of Ultimates and T4 inspirations, and finally got around to using the dozens of temps that I've collected on my main over the past two years that have otherwise sat in my trays unused.
I'm happy to use whatever capabilities that exist in the game to play the game how I would like. Cost is irrelevant in this game given enough time. It's not a learning curve, it's a controlled market. If anyone disagrees with that, I'd like to know if they thought the legacy market was balanced. That's my anecdotal experience with amplifiers.