Hungarian low cost carrier Wizz Air offers cheap flights from Bari to Bulgaria. Tickets to Sofia for only 19.98 EUR round trip.
Sample travel dates:
How to book:
Go to Wizzair.com and choose the routing and dates from above.
Baggage during the trip:
One cabin bag per passenger with maximum dimensions of 42cm x 32cm x 25cm. To get the lowest rates you have to be a member of Wizz Discount Club (WDC).