You aren't likely to find much of anything that's more secure than the builders doors, that came with the house, for under $200 a pop
Security in a door comes from strength and rigidity. Basically you should be thinking about materials like steel and hardwood. Most doors simply don't have the construction to provide security against any sort of real physical attack. A few hits of a sledge hammer, a minute or two with a pry bar. Heck even a sustained stomping with the flat of your foot will eventually take out most residential doors.
You should look at heavier gauge residential steel doors, at commercial steel doors, at solid residential hardwood doors, at fire rated doors with higher ratings in terms of minutes i.e. 60 or 120. Fiberglass and softwood can also be okay under the right circumstances. You will often find those materials in fire rated doors. But the short version of this story is that security costs money unless you have the skills to fabricate or modify doors yourself. It's actually very easy to spend over $200 on a decent lockset. Last time I priced a decent commercial steel door at Home Depot it was over $500 without hardware.
As a starting place, with your builder grade doors, I would consider using something like the StrikeMaster or Door Jamb Armor. If the house has yet to be built, spec commercial or longer duration rated fire doors with steel frames and reinforced carpentry e.g. extra studs, LVLs or 4x6 posts in place of studs.