Sold some stuff in the mid 80's to fund a ski trip. Nothing big, a couple T206 commons and a 48 Bowman set that was mostly in poor condition.
Had a fun trip with friends, and started rebuilding the Bowmans in better condition. Still only at 12 cards, and haven't added one in a long time.
Sold off a bunch of extras and "stuff" like boxes full of rotogravure sections when my first daughter was born. Not to fund anything, but to make some room. Most of it was stuff I'd saved from lots I bought, except the roto sections. Did pretty well with most of it, and put some of the money into upgrading the 1880's house. Some new windows- made the place about 20% more efficient, just in time for oil to go up 20%. No actual savings, but kept the bill from being about 800 a year more than it is. (Yeah, big old uninsulated places use LOTS of fuel to heat) Bought a couple nice cards with the rest, an excellent swap in volume, two cards for maybe 10+ cubic feet of stuff.
I'd echo what others have said about the furniture. I mostly buy used furniture anyway.The old furniture is usually more solid than new stuff and at a much lower price.
Having stuff that crayon will clean off of without it being a huge hassle is great. Some mid century stuff would actually work well. My kids haven't trashed the furniture too much, I did have to replace one couch cushion because of ...Something leaking onto it from a diaper.
But other than that they've been ok. Maybe because they're girls? I was very bad on furniture. Trimmed off the edges of all the couch cushions when I discovered scissors.
Covering cloth furniture with sheets or cheap slipcovers is also a good idea. Less worries about abandoned bits of fruit or biscuits gummed into a gooey mess wrecking the upholstery.
Steve B