The phone maybe cheap but the sim in it is still important. you need to get it back and let the police know that you lost it.
A firend lost a phone didn't care about it for a day. reported on Monday. it turned out it was stolen a day before and used for asking a ransom in a kidnapping case!! the mobile company traced the adress to the original owner and he was arested ... he had to explain why he didn't lodged the FIR right away and that it was not in his possession. He was out only after the kidnapper was traced.