score:4
Numerous carriers fly to Yerevan:
Armavia, AirFrance, Lufthansa, Iran Air, Czech Airlines, Austrian Airlines, Aeroflot and the like. Yerevan is connected to all major European and Middle Eastern cities: London, Paris, Amsterdam, Athens, Moscow, Vienna, Berlin, Prague, St Petersburg, Zurich, Minsk, Riga, Kiev, Istanbul, Dubai, Aleppo, Tehran, Beirut and so on. Air Arabia connects Yerevan to the Gulf states, Egypt and India via Sharjah. Armavia reopened the Route Yerevan - Tbilisi - Yerevan again, with two daily flights last year.
I also checked my trusty S7 Airlines (the English link is at the top left of their page), and confirmed that they can get you there for 197 Euros, pretty much any time of the year.
Even using ITASoftware, the best I can see is 193-196 Euros any time in July (arbitrarily picked month), same for November, same for February, and ... oh...
Now we're getting somewhere, I assumed it might be cheaper later on, but it's actually cheaper this month. Still the best I can see is on May 30th for 189 Euros, with Aerosvit, stopping off in Kiev. That's on a search that includes Aeroflot, Aerosvit, S7 Airlines, Austrian Airlines, Transaero, Lufthansa, British Airways, BMI and many many more, as well as combinations of the above into 'hacker fares'.
So long story short, for now (I may play more later), it just looks like that's the price - around 170 (you found) to 190 Euros, depending on the airline of your choice and route you take.
stats
Farecompare has some 'facts' about this route: