The sewing machine at $300 is $920 today and looks basic as heck. I bought a computerized sewing machine last year for $400 which sews 40 stitches and is basically automated. You could get a basic Singer today for 85 bucks.
Those microwaves would come in at about $1,200 in today’s dollars. Most of us spend about $50 on one today, granted the quality is probably crap.
How did people afford to buy anything back then? I recall my parents getting the Beta Max player, big 30” TV and satellite dish back in the early 1980s (we lived in the country). Throw in a stereo and a few kitchen appliances and I think it would rival what they paid for our house!