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You're right. I fought an asston of Chansey and something slowly got HP EVs that I didn't notice. Maybe it had something to do with the EV reducing berries telling me that there was nothing to reduce whenever I fought something that gave EVs I wanted to get rid of.
E: It actually tells you when...
Don't you mean $80 to $90 since there's no third version? And if you just want the pokemon you can just trade or transfer from HOME without buying the expansions.
If you couldn't tell it was going to evolve the second you saw it being used by a Recon unit I don't know what to say. It screamed NFE. Didn't expect what it turned into though.