Tibor Hollo is selling condos with a take — and maybe leave it — deal. The developer is offering no income, no assets, no questions asked loans for 75 percent of a unit’s value, plus a money-back guarantee. The unit must be in his Opera Tower near Miami’s performing arts center, and there’s no haggling on the prices, which are approximately $400,000. It’s a new approach for a developer who’s stuck with unsold units. Most of the 398 units in the Opera Tower are rented, but even Hollo, a 60-year veteran of Miami booms and busts concedes this is an untried approach.