Pricing oddity

I don't want to out anyone's niche, but perhaps someone could explain this to me.

Rolling in the 10-14 bronze at AE, I got a level 20 bi-aspect IO from a certain ToHit Buff set with three pieces including a perception proc. I almost summarily deleted it. Low level range, meager bonuses (Small S/L Def, meh Regen); I figured it'd probably sell for a few thousand crafted. But I kept it because had never checked it out at the market. I'm glad I did. Last five sales? All 9 digit figures.

Wait, what?

So I crafted it. Salvage cost me less than 10k. Now I'm waiting for the modest list price to fill. When it does, I'll have more inf on one character than I have ever had on my whole account in 6 years. Maybe I should check the recipe prices.

But I still don't understand: How is this being used that it is so valuable?

Probably the Perception bit. People HATE HATE HATE getting Blinded. At least, everyone I run with does.

But the OP says it's the bi-aspect IO going for 9 digits.
Very odd. It's not like people need to use obscure IOs to transfer funds any longer now that we have gleemail.

Speaking of the +perception IO, just prior to the Market Merge and for a short period after, I had 2 characters set up fishing bids on the crafted spanning levels 10-20. I figured with the PvP crowded thinned, maybe I could pick up a few on the cheap and store them until PvP comes around again. I really didn't expect to be able to snag many, though, considering I was only bidding a little more than 50K. As it turned out, I was picking up buckets of them, mainly in the low levels. Eventually I had to cancel my bids since I was getting way more than I expected to store.

I thought I had really misinterpreted the +perception IO's appeal since it seemed like everyone was just dumping them. Looking over the "going rate" across the levels 10-20, they weren't selling for more than 1-2 million and that was few and far between. Until I got to the level 20s. Really, are people that stupid? The level 20s were going for 20 million. I sold off the few level 20s I had picked up.

And, naturally the price has fallen past my then-medium-low listing. Hax!

I wait for another weekend to pass.

As others have said, it's a valuable set for anyone chasing S/L def bonuses. What's better, the only thing you can slot in most +ToHit powers (BU, Aim, etc) for Defense is the 6 piece Gaussian for 1.25% against all types. If you're only going for S/L, you can only spend 2 extra slots on BU and get more S/L Defense doing that, too. On top of that a lvl 50 Rech IO and the ToHit/Rech from that set offer about as much Recharge enhancement as the whole Gaussian's set.

I used two of these sets on my Ice/MM Blaster to get her to soft cap (Perception + ToHit/Rech and ToHit + ToHit/Rech). Then again, I fished the ToHit/Rech's at odd levels and got both of them for 2.5mil a piece a week or two ago.

Most sets usually are most valuable at their highest level which might explain this one being most expensive at level 20. I've also noticed any IOs at levels divisible by 5 are also more expensive than others. I guess people just like to see those nice 5s and 0s when they look at their enhancements. I don't mind because it lets me get my pieces at lower prices!

It's used in a lot of PvP builds as well.

I noticed before the market merger that the proc you're alluding to was going for much higher on blueside than they were on red. I could sell a level 10 for about 20 million on blue but they were worthless on redside. Level 20s were about the same on both sides but the recipes were much more pricey.