Mold count in home air?

I was concerned about a smell in my daughter bedroom. Did not smell "musty" but, could not figure it out. So we called a mold company to inspect the house. They saw nothing of concern even under the house. They then did air testing. The outside reading for Aspirgili mold was 38. Our master bedroom came back at 76. My daughters room of concern 54 and our other daughters room 38. I was so alarmed and upset by this. I asked the company what to do. They wanted to come in and HEPA vac the air and wipe everything down for $2000. I asked though where is this coming from though? They really did not have a conclusive answer for me. They asked well when was the last time you got new carpeting? "We only have hardwood floors" When was the last time you had your air ducts cleaned? "We just got a whole new system including ducts put in 3 months ago! Everyone has told me don't pay to have that done it is crazy. This is a big concern for us though. And we finaly figured out the smell in our daughters room. The area rug she had! I got it washed and no more smell! What should we do? Is this acceptable even though it is higher then outside? We went out and bought a HEPA air purifier for like $300 to run for now. Figuring if they were going to HEPA clean the air we could to.