There's one part of the "buying a house" budget that isn't mentioned all too often and that's the expenses -after- you move in. I'm not even including your bills: taxes, electricity, gas, water, etc. There's also potential roof repairs which can get quite pricey, plumbing issues, wiring issues, and other little fixes. To minimize these (or to at least get an idea of what potential costs there may be) I recommend having a home inspector thoroughly check the house over before signing any paper work. You should always get a home inspector before buying a house, but you really need to do your homework and find one that is very thorough. For example, both of my brothers bought houses around the same time. One brother just went with Joe Schmo inspector and has found nothing but problem after problem with his house. The other went with an inspector who was highly recommended by a lot of people. This inspector wen through every nook and cranny of the house and listed every issue and potential issue as well as potential costs involved. My brother ended up using that to get the cost of the house reduced and used the savings to do the repairs, which saved him a mass of money.
Now that was covering only repairs that will bring costs after closing. Most people are going to want to repaint their house (at least the inside) which can add up. There's also costs if you plan on changing the flooring (or having hardwoods freshened up). Did you want to update the kitchen appliances or the washer and dryer? Yep, those add costs. Though, the best time to do that is actually early Fall, since that's when newer models are released (I highly encourage buying them on Black Friday as the deals are usually killer). Every little thing you want to do to your house immediately after purchase is going to add up into some pretty decent expenses.
There is a lot you can do to negate some of the costs. If you are pretty handy, you can do repairs on your own or DIY some of your furniture. I'm pretty in love with a lot of the pallet DIY's and plan on making a lot of my own furniture.
If you aren't and don't know someone who is you can try to lessen the costs of furnishing your house through purchasing from Goodwill, freecycling, thrifting, and even Habitat for Humanity. I'm a big proponent for buying through Habitat as not only can you get a really good deal on barely used furniture, but you're giving money towards the building of a house for someone a lot less fortunate.
So basically, everything adds up in costs, so not only do you need a "purchasing a house" budget, but also a "stuff I need to pay for after the house is purchased" budget.
