Ukraine with kids in August

We are two moms with 4 kids (6,7,8,9) who'd like to travel for three weeks in August. I am researching where we could go. Have been to Turkey (Antalya area) and Bulgaria (Burgas area). Croatia is off the list as it is too expensive. Romania could be good, but as far as I know the food is quite bland there, and dirty beaches with blaring music do not sound attractive to me. We have a budget per family per day of around 50 euro (15 euro for a clean room with three clean beds and 1 private bathroom, food, and excursions). Is it easy to find rooms when there? What places are worth visiting? Which beaches are good for kids? We'd like to stay in about three different places, and visit around. Any recommendations? Are boat excursions expensive? From what age do kids have to pay? Or is there a reduction for kids? What foreign languages do people speak? (we speak English, French and German) We like good food, that is sungrown vegetables (salads, grilled and marinated) and fresh fish. If you have some good adresses for rooms or restaurants, please post here. Thank you for all your advice.