Remember you will also need enough for closing costs and pre-paids due at closing. Depending upon your taxes and insurance amounts you could be looking at another 3-1/2% to 4% of the purchase price. In some high cost areas, it could be more.
These closing costs and pre-paids come from the buyer. However if you negotiate it into your purchase contract, you can have the seller pay those costs (not your down payment though). The limit on a conventional loan is 3% of purchase price and for an FHA loan max allowed limit for a seller contribution toward buyer closing costs is 6%.
The lender can also pay a small portion, but they have to bump up your interest rate over the life of the loan to do it so be careful with this option
Another option you might look into is first time home buyer programs for your city, county and state. Be aware that these first time home buyer programs have income and asset limitations and sometimes they limit where you can purchase by zip code. Each program has its own rules so look them up first.