Yes, paleo can be expensive! I used to eat mostly vegetarian. That worked for me at the time (lots of bread and beans and rice) because I was in my 30's and I was running a lot.
Fast forward to my 40s, and a second baby (in my 40s), and joint problems from running.
I had a huge HUGE trouble losing the second baby weight. Even on a low calorie diet. So I tried many different things (yay for self experimentation).
I found that calorie levels remaining the same, I lost more weight the closer to paleo/primal that I got.
As a direct comparison, in Sept and October of last year I lost about 1/2 lb a week. I was around 150-154 during that time (I'm 5'2" female).
In November, I gave up bread, alcohol, fried foods, and sugar. Note: I did not read labels, and I didn't eat much of these things before this.
AND - MY CALORIE LEVELS DID NOT CHANGE. (I replaced carbs with fat).
During November I would eat 0-2 servings of "carbs" a day. (Note: I still at 1-2 fruits a day and distinguish those from carbs from grains.) Thus "Carbs" were beans, brown rice, potatoes, sometimes corn.
So a typical "0" day would be:
fruit/protein powder smoothie for breakfast
cottage cheese for a snack
large salad with veggies, nuts, olive oil, vinegar, 2 hard boiled eggs, sometimes cheese for lunch
protein (chicken, beef, pork) for dinner with 1-2 cups of veggies cooked in olive oil, butter, or coconut oil
A little bit of hummus, cheese, or avocado - depending on what I ate that day
A typical "2" day would be a repeat, but maybe 1/2 cup of beans on my salad and 1/2 a baked potato or 1/2 cup of rice with dinner
I lost 7 lbs in November, 3x the rate of September and October.
Note, most of the year I was very resistant to restricting carbs because I'd been taught for 20 years that I should be eating 6-11 servings of whole grains per day (thank you USDA). Then I read "What to Eat" by Luise Light, and realized that that was a made up number, and the real answer is 1 or 2 servings of whole grains per day.
So while I'm not "paleo", I lean more towards Dr. Mark Hyman's "PEGAN" (paleo-vegan). Which means: take the best from both sides, and beans and rice are okay in small quantities.
http://drhyman.com/blog/2014/11/07/pegan-paleo-vegan/A lot of people are anti-paleo, but I personally think paleo is a lot closer to "healthy" than a high carb diet is.
Strict paleo folks have zero starchy carbs a day.
The USDA says 6-11 servings.
Healthy is probably 1-2 for women and 1-3 for men.