I do ~1200 dps while tanking. My gear isn't very good, obviously. However on some bosses I would like to switch over to either Holy or Ret.
If I were to switch specs to Ret and keep the exact same gear, and put in a Titansteel Destroyer as my weapon, what kind of dps could I be seeing, assuming Naxx 10, non-BIS gear? My guess is just shy of 3k, fully buffed.
you won't do much considering your crit will be like 15% or so and with prot gear you'll be missing the majority of stats that help out a ret pally so i'd say in a 25man you'd probably get 2k max and 1.5k in 10man
You will also be missing quite a bit of hit if you change to ret spec with tanking gear reducing your dps alot. what adamson said does not really fit the post, as he asked about prot items on a ret spec; hence you will not be using SotR etc..
I carry a pvp set of items and a nice 2hander with me and when needed i just jump to my ret spec and slap them on.. will do better dps in even "decent" ret gear than being in prot gear with a ret spec. Remember that the mains stats for ret differ from prot quite a bit.
See I'd say stay prot and put on ret gear, I've messed around with this and goten some amazing SoR & Hammer hits. Its kinda fun seeing all your prot spells crit every time haha.
It really wouldn't be very good comparatively. It's super easy to get a good ret set for starting out raids. Here are some tips:
Head: Spiked Titansteel Helm (Crafted)
Neck: Titanium Impact Choker (BoE)
Shoulders: Spaulders of the Giant Lords (Hodir Revered, which everyone should have anyways)
Back: Cloak of Bloodied Waters (BoE)
Chest: Darkheart Chestguard (Ebon Blade Exalted)
Bracers: Wristbands of the Sentinal Huntress (BoE)
Gloves: No Great Options; T7 Gloves are fairly easy to get, though (sarth/badges); prot gloves for the meanwhile
Belt: Belt of the Titans (BoE) If someone has the pattern; If not, you're waiting on the H Nexus drop
Legs: Legplates of Bloody Reprisal (Wyrmcrest Exalted) [note: get the staggering legplates ASAP]
Boots: Death-Inured Sabatons (Ebon Blade Exalted) OR Battlelord's Plate Boots (BoE) if someone has the pattern
Finger: Ring of Scarlet Shadows (BoE)
Finger: Titanium Impact Band (BoE)
Trinket: No good, easy options here. DMC:G is available, if you're willing to drop 10,000ish g, though
Weapon: Titansteel Destroyer (BoE)
Libram: Venture Co. Libram of Retribution (Venture Coins)