Cheap dynamic mic recommendation

hey all

I've never used anything else apart from a couple of shure sm-58s for live stuff and I love em.

but the school my wee lad goes to have a pa system that's currently mic-less and want to buy a couple of mics that are decent quality but that are cheaper - maybe round the 50 quid mark

i said I'd have a look for em, so thought I'd start by asking here - coz outside of shure and akg I'm clueless!!

they're going to be used mainly for public speaking and occasionally amplifying singers/instruments in yer typical school hall setting.

cheap, resilient (think kids in school) and decent enough sound quality

any suggestions would be appreciated - ta.