Effective way to get PvP IOs?

So I've got a purpled out build that I need to meet but I'm not 100% sure how to easily acquire purples without spending billions of influence since I've never tried before. I should specify that this is in regards to purple PvP IOs since I just never really see those around. I have plenty of converters and a bunch of hero merits saved up --- What should I be doing to efficiently get Gladiator's Strike or the Gladiator Armor defense proc, or Panacea? Those seem to be the ones I'll need to get my Stalker to a decent place. Are there any tips?

Ok first off, technically the PvPIOs are not Purples. They have some behavior similar to purples but they aren't actually purples .

Realistically the best way is to buy them on the market. You mention having a decent supply of resources so I'd suggest liquidating some of them and using the Inf to buy the recipes you want. Specifically:
Hero Merits: Trade these for high value recipes like LotG +&.5%s or Numina Uniques and sell those
Converters: Buy cheap Purple or PvPIOs (for purples the mez sets tend to be relatively cheap) and convert them into more valuable IOs. If you're lucky you'll get one that you want but if not you can sell it and use the inf to get one you want. Just remember, in-set conversions are pretty much a waste of converters, just convert out of set until you get something you can sell for a profit.

Now if you want to earn them yourself you can setup an AFK PvP Farm but i can't help you with that.

A slow and steady way if you have any incarnates is to collect empy merits. Once you unlock all the costume stuff, about the only valuable thing to do with empyrean merits is buy purple and pvp recipies. Due to the price difference (the best pvp IOs are double the price of most Purples, but only cost 50% more empy merits) I tend to buy the 3% def PvP IO with my empys.

Also, astral merits are a good source of money. 2 of them and you can buy an ultimate super inspiration. These sell reliable for over 10million each for a value of about 5m inf/astral merit. For 32 Astral Merits you can get any rare recipe (the same as the hero merits Adeon recommended). About the most you'll earn with a rare recipe is 130m inf, and sometimes prices on the top stuff dips down into the 90m range. But if you're patient, you can get a reliable return of a bit over 4m inf per astral this way.

Just an FYI, all of Adeon's recommendations can be done at basically the same time. You earn converters as you kill things and can use them on drops or stuff you buy. And you earn merits (including hero merits) by playing. So it's not a case of pick one and do it, you can do all of them at once.

Speaking of IOs...

I've got some A-Merits worked up, and I was thinking of selling some mid-level PVP IOs. Then I started looking at the market for figuring out which ones to sell, but it seems like no one is selling PVP IOs around the level 35 range (except for occasional procs).

Is this a supply thing, or a demand thing? I get that PVP IOs work when exemp'd, but I figured there were still people who liked to slot sets before hitting 50. Would it even be worth it to create them at lower levels?