I believe that prestige 2's 50% trade penalty is, for the second prestige modifier to unlock, too impactful. It does severely impact the way one can play, just two games up from impossible. This feels like a major hurdle thrown in the player's way too early in the prestige progression - particularly before a player acquired all meta upgrades that may improve trade prices first.
I would recommend spacing that modifier out over multiple levels. There is no reason not to have more incremental prestige modifiers spaced out over more levels - I'd like to see that modifier reduced to 25% for ease of access into the new challenge mode, and adding another 25% at some point at a higher prestige level to achieve the same effect higher up the difficulty curve.
Please consider the context of new players wanting to try the early prestige levels, even on level 5 or 6 before acquiring most meta upgrades, and how difficult a roadblock this 50% modifier is.
A more incremental approach to difficulty increased may encourage new players to play prestige before maxing out the meta upgrades, which I'd love to see, as I think the longer games prestige mode offer, and the cool sacrifice rewards, make this mode so much more rewarding than the default impossible difficulty while leveling.