Retail would be about $40 a linear foot. Plus about $100 for fittings. Doesn't matter how deep it is. You dont need to remove the tile.

Ok thank you. But it doesn't matter how deep it is? Wouldn't it cost more for depth, more to plaster?

I refurbished our gunite a year ago. I believe it was about $20 a bag at Adcock. There is a light blue that is only a couple of dollars more than the white. Ask the prices. I maybe can get you the name off a remaining bag of plaster.
Our pool is also 35,000 and material and labor was less then $2000, because I worked alongside mixing plaster and pouring.

This is something that varies greatly in different areas of the country.
You would really need to call someone local to get a price.

Thanks for your replies.