re: How screwed am I by not putting down 20% on a home purchase?

Here are some realistic numbers for you first time buyers:

Closing costs for $150-200k home are about $3,000 to buy it
Closing costs to sell it are about 8%, 6% to realtors and sub $200k homes often times the seller has to pitch in for closing costs.

So you are realistically looking at $15-20k to buy and sell a house, if you only own it for 5 years that is $250/ month. Add in your insurance, taxes, PMI, etc. and if you don't have 20% down then you are not paying off much principle at all.

Don't forget that not having 20% down you are paying a lot more interest so your payments are higher and you are not paying down nearly as much.

The housing market it high right now. It very well may keep rising who knows, but its also likely we could see a 10% correct if interests rates increase or something else.

I was bent on buying a house asap also, but once you own a property or two you realize its not nearly all you think it should be. There's a lot of money to be made on real estate, but also a lot that can be lost.