I saw this and just loved it. I built a real (rather pricey) dollhouse for Lily years ago so I can't justify making one of these but I think it's great for kids because I've found that the fancy dollhouse I built gets ruined very easily. The pieces are too small, the glue isn't that sturdy and you can only use small dolls in it. This would be great if you have a bunch of barbie sized dolls.
This might be a great idea for a Christmas gift. You can use the Expedit bookshelf from IKEA for $129. But if you want to be frugal I'd look on Craigslist for used one. Looking in my area I've found one for only $40 in Baltimore, one for $50 in Annapolis VA, and two smaller 8 unit sized Expedits for $35 in Philadelphia, one for $30 in DC, and another for $35 in DC. I use Crazedlist.org to search Craigslist. It allows you to search multiple cities at once. You can even search by regions (ie NE, SE, W, Mountain, New England, etc.).
Also, doll furniture can get pretty expensive. By the time it was all said and done, the dollhouse furniture and flooring I bought cost as much as the dollhouse. Some places I've found cheap furniture are the dollar store, thrift stores, Cragislist (see this deal), Ebay's okay too but you have to keep shipping in mind.
It also looks like the person who did this used simple things like patterned paper for the walls and floor and fuzzy fabric for the rugs. You could get pretty creative with something like this. I really like how each room has a 'theme'. I think my girls would just swoon over it.