Ok so I get why upgrading furniture costs credits, but I think SDBs should be more like wallpaper swatches, where once you buy an upgrade you own it. The reason I say this is because it seems that many players are making multiple SDB, not just one or two and to pay 10-25 credits each adds up.
I know we have two free options (black or white), but there are so many fun other ones. I would gladly pay 55-75 credits for an upgrade if I then owned it for multiple SDBs.
From alot of the home images I've seen, people are mostly using only the free versions because they have so many and they want things to match.
just a thought...