One way to get an idea about how the Shearer book is selling is to use Author Earning's data. My guess is they aren't selling more than a handful of copies a year, at best, but it would give an idea of what you can expect and from that you can adjust your price.
Based on this
link, the Shearer book has an overall Kindle rank of 2,888,945 in the Paid Kindle Store (#1751 in the "Kindle Store > Kindle eBooks > Nonfiction > Politics & Social Sciences > Social Sciences > Human Geography" list.)
Using the
October 2016 data (DataGuy hasn't released the Feb 17 data yet) it looks like anything with a rank 200,000 or less will average about 1 sale every other day. (Column AE shows daily sales of ~0.5 at rank 198,559 in column J.)
If you scroll all the way down to rank 2,888,945 (or the closest to it), rows 188,690 and 188,691, you can see that there are around 0.0173 daily sales or 1 sale every 58 days on average or ~6 books per year.
If you price your book the same ($100) and if your sales are the same, and I don't see any reason why they would be much different at the full price point, and you are publishing through KDP you would get ~35%* of the sales or 6*.35*100 = $210 per year. Give or take.
That price point will certainly impact sales though and you will have to decide if you think there is enough demand for your book to warrant dropping the price. My guess is that dropping the price from $100 will have a better than linear effect on sales. Meaning, if you drop the price by half your sales may more than double. Or if you drop the price to < $10 (1/10th), you could get more than 10x the sales. Based on 6 books per year it still won't be many, but even if it isn't the full 10x and is only a 5x increase in sales (30/year) you would get the same amount of take-home since the rate they pay doubles* below $10 per book (and $2.99 or more). 30*0.70*9.99 = $210.
*I am using these percentages from memory and you should double check them with the KDP terms and conditions.