Your backyard should best serve your family. Many pools can be built in between the $20ks and $30ks. And there are some great water features that are relatively inexpensive to add to your design to ensure a smaller budget does not mean a smaller impact.
Please remember that each backyard has unique attributes that will effect your pricing, including the terrain, access to utilities, access to the backyard, and more. So, what may be a $19,999.00 pool in one backyard does not mean that it will be the exact same price in your backyard.