I've been hanging out on the chinese iem threads on HF lately and I feel like a lot of the best values can be had there.

Here's a couple of iem based setups that work for a desktop setup too.  I actually have these iems and they're great.  Sorry I don't have a lot of dacs so I just included the one I have. 

$117 setup
hifimediy uae23 usb dac $42
topping nx1 portable amp $40
Ttpod t1-e iem - bassy $35


$166 setup
hifimediy uae23 usb dac $42
fiio e11k portable amp $59
Havi B3 pro 1 iem neutralish $65

$100 neutralish portable "rig"

Your mobile phone
RE400 modulor modded

$525 beginner's classical rig. (I don't swear by this combo . . . yet.)

GO 450 $200
Monoprice cable $5
Vali $120
used K501 ~$200

My recommendations are not much different from what’s already been mentioned by LFF, Marv, and Claritas. But I thought I’d throw in my two cents in. Used prices for most things because I'm a cheap:

Sub $50
Clip + ($30)
Koss KSC-75 ($9.99)
Parts Express Headband (< $5)

What LFF said. I went with the KSC-75 over the Portapro because of the cost savings. (I also like the sound of the KSC-75 a bit better.) Rockbox the Clip and Quarter & Kramer the Koss.

$300
Galaxy Note 2 (Bad ESN, Used. $100-150)
Micro-to-Mini USB-OTG Cable ($10)
ODAC (Used, $100)
Cmoy BB  ($35)
V-Moda M-80 (Used, $60-80)

This recommendation is a bit odd…but here’s the logic behind it. The Note 2, via USB-OTG, supplies impressively clean power to the ODAC. ODAC sounded far better off of my Note 2 than my Retina MBP prior to getting a Wyrd. The cost of a Note 2 isn’t that much more expensive than a Wyrd – and you get a useful, full-featured portable source. 

From there, I just recommended a budget Cmoy and a M-80 because they are cheap and sound decent. You could substitute any budget amp or budget headphone though, really. The Vsonic GR07 Classic is like…$80 at LendMeUrEars right now. It would probably do nicely too if you don’t mind a bit of sibilance and a brighter sig.

This whole setup costs about $300 bucks. It’s portable. It doesn’t even require that you own a computer. It fits well on a nightstand. You can dual lock it into a stack and carry it in a camera bag. People will mistake it for a bomb on public transit. (I liked this setup even more with a decent pair of DT1350's and a UHA-6.MKII. The Leckerton costs almost as much as the whole rig though, and the DT1350's are over 2x the price of the V-Modas or VSonics.)

$500
Geek Out 450 (Used, $150)
HD600 (Sale, $300)

Exactly the ~$500 rig that I’d use. (Drop the Wyrd if you already have clean power and can’t hear an audible benefit.) The HD600 runs well out of the GO (even though it's amp section is its weak point).

$800
Wyrd ($99)
Geek Out 450 (Used, $150)
Leckerton UHA 6S.MKII (ADA4627-1B, Used, $200)
HD600 (Sale, $300) or Paradox (Used, $300-400)

The Vali and Modi are both cheaper than the GO450/Leckerton and are probably better budget picks. (They might straight up sound better too, but I haven’t heard the Wyrd + Modi combo or the Vali. I hope to do so soon. I plan on buying a Vali in the beginning of December.) That being said, I really like this setup. It works well with portable headphones/IEM’s too; the 6S adds a bit of extra versatility.

I'd like to second Marv's setup and provide a few of my own. Sorry Uncola, but I can't recommend any of the hifimediy dacs. They sound flat and dead to me. As for the hd580... it's tough to say sometimes buying such an old headphone off of ebay and such. You could get a good pair or you can get a shitty one. Best to stick with a used hd600 or a new one.

~$1200-$1600 portable setup - The GO 450 can do decent on its own but the leckerton is better than the GO's amp section. The setup is much more portable without the leckerton however. Wyrd is optional, and reduces portability factor.

GO 450 ($200)
Wyrd ($100)
Ultimate Ears Reference Monitors ($1000 or $800 with meet discount)
UHA-6s mkii w/ ADA4627-1b ($290)

~$800 - Transportable and musical. The GO 1000 adds some nice body to the hd600 sound and has nice clarity even with its added warmth. The 450 would probably work too but I've never tried it myself. Wyrd is optional, and reduces portability factor.

GO 1000 ($300)
Wyrd ($100)
HD600 ($400)

~$2600 - My current setup. I bought most of my things at either a discounted price or used (I paid around $2150 total for this setup). The gungnir and the virtue one.3 have a great synergy with each other for orthos like the he-560. The gungnir has great dynamics, bass body and tone, non-harsh treble, and excellent vocals/mids. The Wyrd does its usual voodoo magic. The virtue one.3 is a solid state but provides tons of power for orthos and has great tonality with clarity and smooths out the treble of the energetic gungnir. The he-560 you guys probably already know about, but the latest jerg mods takes them to another level.

HE-560 ($900)
Virtue ONE.3 w/ 130w PSU ($639)
Gungnir Gen 2 USB ($850)
Wyrd ($100)
Modding materials ($40)