There are no limits on what private persons can buy and take with them when they travel between EU countries, as long as the products purchased are for personal use and not for resale, with exception of new means of transport.
If you enter Bulgaria from a non-EU country, goods having no commercial character can be imported free of customs duties, VAT and excise duties within the following limits:
Tobacco products: 200 items cigarettes or other tobacco products - 250 gr.;
Alcoholic beverages: 2 litres wine and 1 litre alcoholic liquors -;
Other drinks: 500 gr. coffee or coffee extract - 200 gr., tea - 100 gr., or tea extract - 40 gr.;
Perfumes: 50 ml. and toilet water - 0, 250 ml.
Passengers who are under full 16 years of age are not entitled to duty-free import of the commodities listed above, except for medications.
Guns and ammunition, knives and deadly weapons
Dangerous chemicals and substances
Items under special conditions
Animal and plant specimens
Ammunition and guns for legal hunting
Nuclear material, radioactive substances, and other sources of ionising radiations;
No expired medicinal products which are authorised for use in the country.
Live game and genetic material, hunting trophies, shed game antlers, and game
Cultural treasures, including those made of precious stones and precious metals
You can find detailed information on the customs requirements concerning the quantities of goods and amounts of money which can be brought into or out of Bulgaria on the website of the Customs Agency.