For bed frames and mattresses I highly recommend Zinus, I got my solid metal and wood king bed frames for $179 and they look great, over 100lbs, easy to assemble, no creaking. I replaced all my mattresses with theirs also, $450 for king mattress delivered, guests often say how comfy my beds are. (Zinus website or Amazon Carries a lot of their stuff), they also have sofas and couches but personally I’ve never tried them. I recommend IKEA for duvets and pillows, their duck feather down products are amazing (unlike most their other stuff). I use ‘Bare’ brand mattress covers, sheets, pillow cases and duvet covers which I really like.
As for other furniture, I’d look at local big box store places (medium price medium quality), or more ideally local custom furniture shops and restoration stores (I bought a bunch of restored 1950’s-1960’s loveseats, side tables as they are heavy duty and higher quality than what you can buy today while still being ‘affordable’ and comfy.
You can read my reviews to see how guests have mentioned the comfort of my beds and other things. (Note the couch/loveseat pictured in the first one are hideous and have been replaced a year ago). (Condos $8,000 to fully decorate/supply/furnish. House was $15k)
www.airbnb.com/h/spokanes-best