Here is how they system works......
They need your money.
They try and take your money.
They don't care if they are taxing you out of your home.
Few people fight. Most of those that fight do win, or win some. I would encourage you to fight every year. Every single year.
"Appraisals" are the opinion of one person, based upon personal preferences of perceived value. The "Appraisal" system is crooked. Last year the appraiser I met with told me that my roof (shingle) was better than a metal roof because it had more points. It was one persons opinion that couldn't be substantiated with any facts. The fact is that almost any metal roof will cost more (or add more value) that a shingle roof of similar size.
One thought I had is that with about a 50-70 hour time investment and about $1500 bucks you could become a licensed appraiser in the state of Texas. At least that way when you fight, your arbitrary opinions are equally weighted as their arbitrary opinions.
You gotta go in there with a Colonel Slade (Scent of a Woman) - "I'm going to take a flamethrower to this place" kind of an attitude. You don't have to be rude, you can be polite and respectful, but the whole system is corrupt, not based on logic or facts, and is designed to relocate your money into their pockets.
You can't state what it would cost to rebuild my house in today's market with any accuracy. Nor can you state what it would sell for until it has sold. Those are guesses, not facts. And I won't stand to have my taxes raised without facts.
I've long advocated on this board for property taxes to be locked at purchase value for the period of ownership, and when the property is sold the new value becomes the taxable value. Anything else is speculation.