I'll replace a lost item once then they have to do so-wall that's my general rule of thumb. Sometimes is I think they have been extra careless they have to pay half if the replacement. They are actually pretty good now though.
Just dint get me started about items left on buses fortunately all were found!
DS is pretty good to be fair but did once lose him PE kit which consisted of brand new football boots, new rugby shirt, shorts he had only had one term - having ripped previous pair - and rugby socks. I found that telling him how much everything cost and that he would have to pay for the replacements himself (together with the thought of wearing the ones he had grown out of for a while) focused his mind to retrace his steps around the school. It took him 2 days to discover he had left it in the History block and it had not yet made it's way to lost property. I was amazed to get a text from school last week about the number of coats in lost property - presumably only worn because of the extremely cold and snowy weather we had been having. I mean how can you wear a coat to school in the snow and go home in the snow and not remember that you had been wearing a coat that day!!!!
DS (age 13) seems to be constantly losing his (and sometimes our!) stuff. Its bags & coats and tops & fountain pens etc. Today he borrowed something of mine (a fancy dress item for a rehearsal) and he has just texted me to say he has lost it .
I know stuff does get lost (and nicked!) in a big school, but it's his blase attitude to it that pisses me off.
What do you do? Do you punish/ make them replace out of own money?