as little as possible mate i just lost ma job too god dam resession bollox
yeah m8 this country is fucked right now so many are losing there jobs etc.
as for a setup well if ya a 1st timer soil is the way to go, and personally i would just get a 250hps or 400hps cause your get so much better weed n more of it with hps.
and also you can use the hps for veg n flower with cfls you would need the 2 bulbs red n blue a good cfl with both bulbs cost about £120ish where as a cheap 250hps will be 70-80ish.
then your gonna need good soil and nutes i carnt recommend bio-bizz all mix soil n there line of nutes more than enough they r very good n very forgiving for a beginner.
as for space well that all depends on how long you plan to veg them before flower?
there r other expenses but thats the basics lights/soil/nutes.