We bought our house with an inground spa in the spf birdcage. I love it. We use it at least 4 to 5 days a week. I turn down the heater in the summer, raise it when it’s a little chilly. We maintain it ourselves. Very simple.

Ambivalent
 

No matter what else get the cage.
We've had our own pool which we barely used and we also had an inground spa without a pool.
Now we have a large screen porch and miss the cage and pool.
If I was in your position and cost was not an object I would get the heated pool with attached spa, and a large enough cage to move around all sides of the pool. Size largest cage and then size pool & spa to fit. IMHO

I agree about getting the largest cage your yard will allow within reason. That can allow for room to have seating around the pool and spa, perhaps an upper level with a waterfall or two, and a grill in the corner. Look upon it as your water view.

Having a pool is totally personal. Some love them. Some don't. If you decide to, get it heated, have a motorized cover for it, consider a built in cleaner instead of a robot style, and consider a built in hot tub if you decide to have one. We chose not to. We bought a small hot tub to try out while we waited for the design and during construction. Two months after getting it, we sold it and that was the end of having a built in hot tub for us. We just painted the floor of the lanai and under the bird cage. We also chose to only have a 1" drop from our main house floor instead of the standard 3" or 4", which ever is standard. Have them install electrical outlets in the columns on the corners of the lanai.

How much money are you willing to spend and how much work are you willing to do? If your answer is lots, then go for it. It’s your choice.

Go for a pool with a pour over spa. The designers will explain what that is. I used our spa almost every night before going to bed.

Don’t get all uptight about the cost of heating the pool. I had five solar panels installed by Jack’s Solar (the best!). I never changed the temperature setting from 85 degrees. There was no additional gas cost for about eight months a year. Even during the coldest month or two it only cost about $200 per month over our normal natural gas bill. The solar alone would keep the pool temp between 70-75 degrees.

Go for it! Don’t get too uptight about incremental gas cost. Get solar and the total additional annual cost will in the range of only $1,000 or so. Easy decision for the enjoyment of a pool and spa.