Everything you have written in your question does not appear suspicious on its face. It is not unusual for people to change real estate agents. It is not uncommon for a home to take many months to sell. It is not unique for a buyer to make an offer well below the listed price. It is not unusual for an agent to be involved with a friend or even a relative. If it were a relative, they would have informed you of that fact. It is not required to inform a seller that a buyer is a friend.
Here is a link to an article about what a real estate agent does all day. I cannot think of why a real estate agent would try to discourage a sale or keep a home from selling deliberately.
They have many responsibilities, and the less time they invest and the sooner they can find a buyer the more profitable a transaction is for them. They know if they were involved in a conspiracy for a small percentage of $15,000, it would be very little money for the loss of their livelihood.
Real estate values for every home are a range of value, not an exact price. The definition of a range of value is the lowest price you should expect and the highest price you can expect. Here is a link to an article that describes home valuations. It is also possible that it took time for your home to find the market-incorrect initial pricing.
It could well be that agent No. 2 leaning hard on you helped you.
If you had not accepted the offer, you would’ve extended the marketing time even longer. Was it in your best interest to continue to wait? And had you waited, there was no assurance that the next offer would be higher in a future sale. It may have been lower.
Your suspicions may be true. But, based on what you have written, it is unlikely. If sometime in the next year the home is sold to an LLC owned by the agents and/or the lender, it would be time to go to the regulators. Here is a Department of Justice list to file a complaint.
