3D interactive functionality

if you look on this site they have two features in the middle of the page called 3D Kitchen Designer and Edge Tool. i need to create similar functionality for a new website and want to get my head around what’s involved in building these.

i’m assuming its done with javascript?

how complicated is it to build something like these tools? if i were to post the jobs on a freelancing website, whats a rough estimate of the amount i would need to budget for?

please advise. thanks in advance.