Welcome! I count calories and you can actually start a lot higher than 1500. I started counting calories in January and I put my stats into a bunch of different calorie counting calculators to see what calorie amount I should be eating at. I modeled my calorie counting off of this one in particular: http://www.freedieting.com/tools/calorie_calculator.htm
The reason you should start out eating more calories is that once you start losing, you may hit a plateau because you weigh less, but you are still taking in the same calorie amount. If you hit a plateau (which is longer than a few weeks), then you may have to reduce your calories to jump start your weight loss again. You have a goal of losing 70 pounds, so if you stall out a lot, you'll have to reduce calories, and you don't have a lot of wiggle room to go down if you start at 1500.
To give you a comparison, I weighed 196 when I started counting calories and I would eat 1700-1850 every day. I lost almost a pound a week. Now that I have lost some weight, I have dropped my calorie amount to 1600-1650 because now that I weigh less than I did originally, I need to eat less calories to keep losing weight. I was stuck at 182-185 for weeks until I dropped it to 1600 and saw the weight start dropping again.
If you are comfortable at 1500, then by all means stick with it...but it's nice to know that you can actually eat a lot more and adjust it from there! It's scary because we think that eating more calories is going to cause us to gain weight, but calorie counting has such a huge range.