It’s probably not beyond the means of most of us when setting up a business, but if it is, it’s possible to acquire office furniture for free. If friends or relatives don’t have furniture lying around you can have, there are places online you can go to get kitted out for free.
Freecycle is an extensive international giving-network where people advertise anything they’re looking to get rid of for free. You’d be surprised what you can get there and all you have to do is respond quickly and be prepared to pick it up. Visit their homepage then enter your location and that’ll direct you to your local group where you can see what’s being offered (and join).
It’s also worth watching Gumtree and Craigs List. Both these sites display classified sites where bargains can be found on office gear. Both have apps available too and will recognise your location to show you only local offers.