A lower bound for A_p exponents for some weighted weak-type inequalities

We give a weak-type counterpart of the main result in an earlier work of the first author, E. Rela and T. Luque which allows to provide a lower bound for the exponent of the $A_{p}$ constant in terms of the behaviour of the unweighted inequalities when $p\rightarrow\infty$ and when $p\rightarrow1^{+}$. We also provide some applications to classical operators.