Parents and I have property that is surrounded by commercial

Back story: My parents bought an acre lot with a house taking up around 2800sq/ft of the acre lot back when it was surrounded by agriculture land.

Fast forward a decade or so, the surrounding land has become commercialized. And by commercialized, I mean there are restaurants, a hotel, and even a sports complex literally right across the street (and a major highway i10 in Arizona within half a mile from the property).

Investors were in the process of buying our land, all the while I was witnessing construction all around us, turning the agriculture land to roads for lots and buildings and stuff. And then the 2008 crisis happened and everything stopped abruptly. And the deal never closed.

I was wondering how do I go about selling our land today? I'm new to the whole REI community, so sorry if I'm being a bit naive.

My dad thinks the property is worth $1.5 million and says he WILL NOT sell if he doesn't get his price. But I feel like he's being delusional and just picking that price out of the air (which would cost us potential sales)? How do I accurately estimate the price of the property (I look up on Zillow/Redfin/etc... and the price is estimated around $250,000, but I think that is very low and inaccurate because it doesn't take into account the potential commercial value of it).

How do I go about accurately estimating the value of the house and finding investors willing to purchase? Do I hire a professional to appraise the house? And if so, how could I go about doing that if I don't have much funds.

Again, I am still learning REI from scratch trying to wrap my head around the details.

I truly believe this land has potential, I just don't know how to proceed. Maybe some tips on learning material might help? Thanks!