2 tiny questions about boy's hair highlights (dye)?

hi there, im just wondering


how long should my hair be to highlight it with permanent blue dye? its 2 inches tall now


and usually here in the uk how much will they charge me?





thanks!2 tiny questions about boy's hair highlights (dye)?
i think it might be around 25 quid if you want to bleach it cheaply. but properly done at a special salon could be a lot more.