Fortunately Armenia is such a small country with so many helpful people it is almost impossible to get lost, and even the most rudimentary maps get you where you’re going. As tourism increases, the "secret maps" are beginning to be mass produced and sold. Already, two quite adequate maps (1 centimeter = 5 kilometers) of Armenia and Mountainous Karabakh were printed in 1994, with reprints in 1997, 1999, 2001 (the topographical map is in Armenian), and can be found at book shops and in the Vernisage (between $5-20). They are meant to be wall maps, so you either "roll and stuff" or "fold and stuff" when you travel.
New maps continue to pop up, so it will be little trouble finding a map in Yerevan. Outside Yerevan it is still a difficult task.
Simple maps of Armenia and Yerevan are available in Russian and English at most newspaper kiosks ("terteri kerpak") in the center of Yerevan, Giumri and Vanadzor. City maps are called: "Karaki Kartez", regional maps: "Sherjani Kartez," and for Armenia: "Hayastani Kartez."
News kiosks stock at least one version of a Yerevan map, which cost between 2000-5,000 AMD.
All hotels will have a basic map of Yerevan which is generally all you will need if you plan to stick to the main streets and sites. No maps show detailed street by street views outside of Central Yerevan.
Prices vary between a few thousand drams and $20. In Yerevan, street side sellers at Vernisage and in the park by Metro Yeredasardakan (the corner of Terian and Isahakian Streets), sell the two mentioned above as well as large USSR, Soviet Armenia, and Historical Armenia Maps, as well as some tourist books from the Soviet era.
An interesting map showing the locations of historic monuments throughout Armenia is available at Echmiadzin and Vernisage.
Republic Square (09.00-17.00) - expensive
At Kaskad (09.00-17.00) - moderate
25, Abovian St. (09.00-18.00) - moderate
On Mashtots opposite Avia Trans tickets (10.00-18.00) - moderate
Artbridge Cafe on Abovian (just above Tumanian) (08.00-22.00) - expensive but good selection
In Vanadzor and Giumri, there are cheaper book shops that also stock old maps, but the selection is limited.