The biggest boon to my traveling was a) go to cheaper places b) AirBnb c) off season or shoulders. Croatia is amazing and inexpensive, although I would make sure to go in the summer to experience the beaches. Hungary is the same and is nice in the fall/spring. Slovenia is a beautiful country. Even Prague can be affordable on the 'shoulders'. Flights are still pricey, but even they are cheaper if you avoid the 3 months of the summer.

I have even touched on SEA which appears to be the younger persons favorite inexpensive place to go.