No need for luck with this search. Those saying that are just disinformed. Not sure what the forum etiquette dictates as far as posting links but here's one place in Sowal off 98 that has new homes (not townhomes or condos) starting at $169k and also offers rent to own. plantationsantarosa dot com.
Also, I think you might have luck with Church St Village. They have new homes in the price range of low 300's for sure, and I think some are even in the 200's right now. And they would probably talk rent to own with you. I would give you more definite info on that but their website has been down for a while (kruserealty dot com). If you want more info on that you could pm me. I didn't want to put his contact info all over without consulting him.
If you include condos and townhomes you have more options. There are 96 properties from 100k-300k listed on destin123 dot com in Santa Rosa Beach alone. But most are townhomes and condos in that range, just a few houses.