Do my family and I need to have 20,000 Baht each time we bounce on our Thai visa, or is there a family rate?

Jen Jen posted in another thread

we are looking to leave NZ for around 12months, traveling on our savings. probably spend most of our time in Thailand then maybe spend the last few months in laos or vietnam or something like that.... completley unsure atm, depends on how long we can stay in Thailand as to how we spend our money lol :)

I had read about the 20000bht - each time we bounce does that mean we need to have 20,000baht each (2adults,3children) - or is there a family rate? - and does that apply each time we bounce wihtin the metv 6month period, or only afterwards?