Most of my high-value relics have came from "oh sh*t" moments where the raid didn't go as planned.
But if I was interested in losing units for a chance of obtaining Rare & Legendary relics, what criteria and avenues would I want to pursue?
How much offense/defense power needs to be sacrificed? Or, how much in total resources is needed? What avenues would I want pursue to exercise the criteria?
m not sure but I know crowbar is an expert on these type of issues he'll respond to you.
No, that would been a question for someone who had loads of "oh sh*t" moments and has been writing that data down. 
My impression is that it's not very constant. For example, for hits worth 10k, 12k, and 16k of PvPs, I got Aztec Gold, and Magic Anvils for about 7-8k points, but I also got Kraken's Claw on hits for 17k points and for 38k points, and I got Aztec Gold for a 37k hit and for a 132k hit (so, 10 times more than aforementioned 10-16k). I don't remember if I got another relic soon after that last mentioned hit, but it was a defensive hit. No idea if that plays a role.
Also, if you do several hits in a row, you may not get a relic right away with a big hit, but you'll get one soon after (even for a small hit), almost as if relics have a "points bank" (similar to "res bank" for prizes). For example, I've had 30k hits with no relics won, but then I'd get a relic soon after with very minor hits.
This is just a hunch. I might be completely off, I might be spot on. Probably somewhere in between.
In my opinion, don't bother with relics. Their bonuses are not big, and - with time - you'll end up with those you like without chasing them.
Those you don't need/want, sell them. I suggest selling all the timed ones, plus those you have more than 2 of and those you know you'll never use.
Anything from the lighthouse get rid of. Both those scout relics are worthless.
On the topic of getting high level relics. It depends on attacks or defensive scenarios. Generally you need to be in the ball park of at least 1 million in an offensive or defensive action. So obviously some sort of pvp is required, including bastion or presidio hits. Also pay attention to the cost of applying the relic. Like the anvil it boosts maurader production speed by 5% but also increases cost b y 10%.
Icy said:
Also pay attention to the cost of applying the relic. Like the anvil it boosts maurader production speed by 5% but also increases cost b y 10%.
Simply deactivate it when clicking new Mars, and reactivate it right after you're done with adding them to the queue.
