in memory of sugar said:
That's beautiful!

Maybe 10k-20k?

WildWillow said:
If this were my piece, I would charge 30k.

There are a few things I can notice that if it were my piece I would change.

You definitely need to work on having the lighting on the horse blend into the background. For example, on the horse's belly and legs there is a yellowy-green tinge. Either from a stain on the stock horse or reflection from grass. Since the horse is in water, the reflection should be blue.

The lighting coming from the left side of the background is yellow yet the highlights on the horse are blue. The white blur around the horse also does not make sense on the backside of the horse since the light is coming from the left side.

The mane and tail look good. Although, it does look like you forgot to cut out part of the original stock horse's background between the back leg and the tail. From what I can see, it looks like there is brown behind the tail. I am unsure exactly what this is, but it does look like the stock horse's background.

The horse is walking through the water so there should be ripples or splashes in the water. In the reflection, the hooves should not be visible since the hooves are under the water. I do think lowering the opacity on the reflection could help as well.

The last thing I think you could change and it would increase the price of your work is working on horse prep. The lines on the horse's barrel needs to be smoothed out. It looks very rigid and looks like you smudged down. In other places, the smudging looks inconsistent. At the bottom of the horse's barrel, it looks like it wasn't smoothly cut out. Take your time - it may seem like it takes forever but it really makes a difference! If the stock horse's barrel was actually formed like that, it is okay to "sculpt" the horse or trim down a bit farther to make it look smooth. I do this a lot in some of my pieces!

Overall your piece is very stunning and I love the idea for it! The grey horse definitely the perfect color for this background. :) I can't wait to see some of your pieces in the future and how you improve.