Business is business… That is why as a landlord I would never rent to family or friends.
If you want to do your friend a little bit of a favor tell him you will offer him the 300k and you will buy the property without representation. Thus your friend will not have to pay the commissions to the buyers agent, nor will he have to pay the commissions of a buyers side to his listing agent. So you will be getting a better deal for your friend. Of course his listing agent may not like to do a transaction with a buyer who is not represented. This opens the listing agent up to liability issues.
Also don’t raise a stink if in the future you find out something bad about the property. It is entirely up to you to perform all the necessary due diligence without representation.
I have done a sale where I represented the listing side and the buyer was not represented. However the buyer was a contractor and he ended up doing more due diligence then many buyers I have seen represented by the big name full service brokerages. However, if it was just some guy on the other side, I probably would not risk it as a listing agent. To much to lose.
Anyways, you can give it a shot to see if it works. Can’t hurt right?