Just some questions on electrolysis

Hiya, well I’m here to just ask some simple questions about electrolysis like costs of it etc. Iv’e just turned 17 and having to wait until im 18 but I figured I might as well find out early about possible costs etc.
Basically I have a large ammount of body hair from head to toe, at the moment I’m using a epilator to remove the hair (unfortunatly the doctor/endocrinologist refused to give me anything for it and mumbled something about me being to young etc.).

I basically want my back and buttocks hair free, then the rest of my hair on my chest, legs and upper arms thinned out so it’s much more sparse. I don’t know whether this is a real expectation or not but anyways.
Another question; if this is possible, how much would it cost round about (as in, will it cost over a couple of thousand pounds etc.)?
And umm how many hours does it usually take to clear large areas like these?

Thanks for your time,