Any variance is usually a reflection of good or bad management. 

The prices are a bit better however the quality of the homes reflect those prices.

That's a direct reflection of the market, though, so pretty tough to argue with their numbers.

Quickbooks shows the payment applied as income, but that amount already reflects some expenses taken out from Property Management.

The PM company's accounting should reflect that.  

ZIllow may work OK, but there is probably a better / easier listing of SOLD properties, remember that sellers concessions may be reflected - don't know what that is?

Yury,I posted something a while back that was a reflection on things I learned after I got started. https://www.biggerpockets.com/forums/12/topics/472645-the-best-advice-i-ever-received-paying-it-forward

Engaging with tenants to understand their needs and preferences can help in tailoring services and amenities, thus enhancing their satisfaction and loyalty.Key Takeaways:Implement tenant engagement programs to build community and loyalty.Regularly review and update lease agreements to reflect current market conditions and tenant expectations.Diversification of Investment PortfolioDiversification across different types of CRE, geographical areas, and tenant industries can mitigate risks associated with market fluctuations.

Laws are updated frequently, and this information may not reflect the current law in your state.

Many properties are sitting on the market for over 1-2 years if not more, however because it's nearly impossible to get a mortgage to buy here and everything was bought cash people do not lower their prices accordingly to reflect the demand of sales.