Splitting rent

Hey all, this is my first time renting and I’m hoping for some insight.

I have four roommates, and two of them decide that they were ok sharing a room and us splitting the price of a 3bd instead of a 4bd.

The home is cute, quaint, and older. It’s priced at $1550/mo, so splitting that between four people would come out to $387.50 per tenant. It makes sense though that the two people sharing a 12x13 master bedroom/bathroom would pay a reduced price.

My roommates figured that these would be fair splits:

Renting the 12x13 together: $300 each

9x9.5: $450

12x10: $500

That just seems a bit unfair to me in the 12x10 and my other roommate in the 9x9.5, we would be sharing a smaller bathroom but paying an increased rate of >$100 and >$60 (compared to the quartered 387.50)

Am I being unreasonable? I don’t want to sound rude or like I’m trying to take advantage of anyone. I want to be fair, but I feel like I’m footing a lot and not getting anything worth the extra $100.

Thoughts, past experiences or words of advice??