Darkvision magic items ?

[Istar]

Okay there is the level 14 googles that give you dark vision.

Any thing of a lower level that you can use.

 

[boolean]

It's possible to use the compendium (here for a search, even if you aren't a subscriber (subscription allows you to click on the results to get more info).
So, a search for all items containing the word "Darkvision" in the description gives the following:

Cannith Goggles		Head		1	360 GP 		Dragon Magazine 365
Hunter's Flint		Wondrous	2	520 GP 		Adventurer's Vault
Cat’s-Eye Headband	Head		6	1,800 GP 	Adventurer's Vault 2
Mask of the Eye Leech	Head		8	3,400 GP 	Dragon Magazine 369
Graefling		Weapon		8	3,400 GP 	Dragon Magazine 375
Bag of Tricks, Gray	Wondrous	8	3,400 GP 	Adventurer's Vault
Circlet of Revelations	Head		10	5,000 GP 	Adventurer's Vault 2
Unguent of Darkvision	Consumable	11	350 GP 		Adventurer's Vault
Eyes of the Deep Dwarf	Head		11	9,000 GP 	Psionic Power
Totem of the Night	Totem		12	13,000 GP 	Adventurer's Vault 2
Netherdark Shield	Arms		13	17,000 GP 	Dragon Magazine 365
Goggles of Night	Head		14	21,000 GP 	Multiple Sources

I doubt that all of them are useful (e.g. the bag of tricks is showing up because one of the animals it conjures has Darkvision), but it should get you started.

 

[Brys]

Not really what you asked for, but there is a Multiclass feat (Haunting Shade, Dragon 387) that grants Darkvision out to 5 squares and you can get it at level 1.