the heating pad saves you about 50 bucks so that's a pretty good deal. Imo if it's not at least 30 inches wide skip it. Anything thinner is probably more likely to break for a budget brand.
Here's what I found closest to your price range while still maintaining reliable quality. My only concern is they haven't had a review in a while and it isn't sold directly by amazon. The reviews they do have seem to be for an older version of it as well (earthlite, and black). If it is indeed the specs advertised then you'll love it. If the color is a deal breaker just find sheets that you like to cover it with
https://www.amazon.com/Inner-Strength-Portable-Massage-Package/dp/B000OGX930
Inner strength is part of earthlite and this includes their good cradle/pillow, it's well priced, 30 inch wide, and case included