richard, for around 500 or less you could buy very pro machine with output around 8g not in mg from poland.
there are realy good machines giving good effect, comparing the ones from uk and their prices i must say uk ones are a toys. no need to be such a patriot and source only uk market
your choice off course
but with an ozon generator for 1000 from uk you need to make a treatments for a day or more as a ozon concentrate in the air can not get advised level for odour removal. the one for less from poland will get you very good efect in 2hrs, depends on room size