Do you guys find this a decent money sink?
Not really. I've spent a little under $15k, and it's looking LOTS nicer than the Solitude home I have in my PS3 gamesave (I'm going to trade that copy in). So, it's a much more economical choice.
My only issue is lackluster "furnishing" when you drop all that $$ to your steward (I paid her $2.5k to furnish the alchemy lab, and all I got was a few wall shelves & the alchemy table, which is hardly $2.5k in materials, as the most expensive item was a single moonstone ingot). Now THAT will be a money sink: dropping coin to your steward who is using it for jack diddly squat.
I am enjoying putting all the time in, however. Makes it feel worthwhile, not just a shopping trip like it is with the vanilla homes.
The bard svcks, though. Another $1.5k wasted. The carriage, however, is REALLY worth it: you get free access to all the major cities, plus lots of the smaller stops.