This decision will come down to what you really want.
If you want to assure that you have your best chance of being admitted this year, and are not against paying out-of-state tuition for this opportunity, apply to at least a few out-of-state schools as well.
If you are dead-set on attending your in-state school out of obligations (financial & personal), or utmost love of that school, you will likely be unhappy out-of-state.
Some people I know absolutely refused to apply out-of-state, for both monetary, family and other reasons. Some got in first try, but a few did not. One person applied in-state 2 years in a row, then became so frustrated that she applied and went to a Caribbean school because she was pretty assured she would get in. While she appreciates her new school and education, she regrets not having applied to out-of-state schools to begin with because she would have saved money.
There are some schools that accept 4 out-of-state students. Unless you have amazing GPA & GRE scores, and some really good experience, it's probably not in your best interest (financial and time-wise) to apply to these. Check each schools info and choose ones that have high proportions of out-of-state students. (From personal experience, Illinois, Mississippi, and Kansas have fairly high out-of-state proportions)
Personally, I was denied from my in-state school two years in a row, and was admitted to two out-of-state schools on my first time applying to them specifically. Live and learn!