Caligula, I think mj0 is being rather hard on you. 10 years ago I went to Rome for a week from the U.S. and spent under $500 for everything, including the flight. I don't expect anyone to do that today.
Last year, my husband and I went on a year-long trip to 26 countries in Asia, Europe, and the South Pacific. Our total costs were $36,000 ($18,000 per person). But we had the advantage of a lot of flexibility in our itinerary and the ability to pounce on deals. Obviously you can very easily spend $3000 in Europe, especially including flight prices from the U.S.
One thing that can be helpful is signing up for some of the really good airline credit card deals. My husband just got 60,000 AA miles for spending $2000 in 3 months with no fee for the first year - and it's only 40,000 miles to fly round trip to Europe from Oct 15-May 15. One of the best uses of miles, in my opinion. Just avoid flying on British Airways with those miles (use AA or avoid London) because their fees for using miles are horrendous. Last time I flew to Paris one-way for 20,000 miles and I think the fee was either $5 or $10.
Also, if you're going to be spending some time in one spot for a few days, I loved using airbnb in Europe. I've found it to be more expensive in the U.S., but in Europe, some of the apartments I found were much nicer and cheaper than hostels. Plus you get to feel more like you're living there than just visiting and have a kitchen to cook in.
And great work on cutting down your budget so much. Fantastic work!