A week in Turkey, mid-range, two people sharing. Four nights in Istanbul and three in Cappadocia, with a domestic flight between them. Hotels €70–110 a night, meals €25–35 per person per day, transport and sights €15–25 per person per day. Roughly €700–950 per person for the week, before international flights, plus €200–300 if you take a balloon flight.
A week in Andalucía, mid-range. Three nights in Seville, two in Córdoba and two in Granada, by regional train. Hotels €90–140 a night, menú del día lunches at €14–18, tapas dinners, and the Alhambra booked in advance. Roughly €900–1,300 per person, and materially less outside high summer.
A week in southern Italy, mid-range. Three nights in Naples and four in Puglia and Matera with a hire car for the second half. Hotels €90–160, meals €30–40 per person per day, car and fuel €50–70 a day split between two, Pompeii and the Sassi tickets. Roughly €1,000–1,450 per person.
For comparison, the same week done in Venice and Florence in June, or in California with a hire car, lands closer to €1,800–2,600 per person. None of those trips is better than the others — but knowing the ratio before you choose is worth more than any individual saving.