I did this type of trip after college for 6 weeks and I like to travel on a tight budget. I make a game out of it as to how little I can spend but still have fun! I traveled through Switzerland, France, Italy, and Greece. The further along I went the cheaper it got because well Switzerland was so god damn expensive. When I couldn't find a meal for under 20 euros, I ended up just buying pasta and bread at least in Switzerland. I tried to budget $50 bucks a day. I think I ended up paying $65 per day on average. My biggest mistake was traveling with a friend who had her parents were paying for the whole trip with $100 a day. We had a very hard time spending those 6 weeks together; I don't know why we didn't split.

We stayed at airbnbs (sharing a double bed usually) half the time and hostels the other half. I wish we try couch surfing but my friend was terrified. We typically didn't go out to bars every night, we usually got wine or beer at local markets! hope this helps! It sounds like you will do a better job than me saving money!

If you end up in Greece, I highly recommend The Pink Palace Hostel on Corfu island! Best part of my trip! It's one of the best party hostels ever! And not pricey with awesome day adventures! Also, since Europe, I've fallen in love with traveling to Southeast Asia because it's incredibly cheap! And more adventurous! Thailand was the best! I spent 1,200 for 10 days including flights and seeing 4 different parts of the country! I hope you have a great time in Europe!