[please excuse my bad English][I read attentively your initial request, but I did not read all the member’s answers dut to lack of time].
Given your constraints, I think it is pretty simple:
- if the new ones MUST NOT be more expensive than the M30.1s => keep your M30.1s (moreover, you like them)
- else, if the budget can grow a little => buy the M30.2 Anniversary 2nd hand. Terrific, but not easy to find 2nd hand.
=> M30.2 Anniversary are the less risky option.
I think it is as simple as that.
Given your constraints, I think it is pretty simple:
"I’m only looking to buy used and not spend much more than what I can sell the 30.1s for. And to be honest, I will only be switching for the sake of trying a new flavor. I really like the 30.1s and something tells me that I might come to regret the decision."
- if the new ones MUST NOT be more expensive than the M30.1s => keep your M30.1s (moreover, you like them)
- else, if the budget can grow a little => buy the M30.2 Anniversary 2nd hand. Terrific, but not easy to find 2nd hand.
"So I won’t be able to buy something else, compare, and resell the one I don’t like as much"
"... switching for the sake of trying ..."
=> M30.2 Anniversary are the less risky option.
I think it is as simple as that.