My CPA requires Quickbooks online and it seems there isn’t an easy way to do the data entry and allocations and keep those two systems inline with all the transactions.  

Here is what one of my 4 AIs say:The commission structure detailed in the image for a real estate transaction involving a property valued between $30M and $40M is as follows:Under $34,000,000: 1% (0.50% per side)$34,000,000 - $34,999,999: $400,000 ($200,000 per side)$35,000,000 and above: $500,000 ($250,000 per side)To evaluate whether these commissions are fair for a 112-unit apartment complex valued between $30M and $40M, let's compare them to typical real estate commission rates for large commercial properties:Typical Commission Rates:For commercial real estate transactions, commissions generally range from 1% to 3% for properties valued above $10M.

While I have a Broker license, I've don't do any buy/sell transactions.

I have several friends that have closed hundred plus of transactions and they asked the seller when do they want to close.

Fingers crossed for reasonable pricing!

Challenge is, finding a PMC that meets your expectations and is organized well enough to consistently deliver.Read on for our copy & paste advice about screening PMCs:-----------------------------------------------------------------------------Recommend exploring as many sources as possible to get referrals AND cross-reference them to get as much accurate information as possible.Check out NARPM.com, BP’s Property Manager Finder (BiggerPockets: The Real Estate Investing Social Network), etc.Also, encourage you to learn from the mistakes of others - by reading posts here on BiggerPockets about owners not having their expectations met by their current Property Management Company.

The fee should be relatively small compared to the investment in a meaningful direct mail campaign.You may also want to chat with a few title companies about what kind of transactions they'd be comfortable with.

Keeping my fingers crossed that he is able to sell some of these properties at profit.  

In any case there is no taxable event yet.As far as your brother is concerned, it again depends on the nature of the transaction. 

There's lots of tax planning on this and I would suggest to take a professional opinion on how to structure a transaction in a way that you can make it into capital gain tax or reduce self-employment tax.