Portfolio Wholesaling- Assignment Fee Question!

[Matt Miller]

Hey BP fam,

When wholesaling an entire portfolio, what is the appropriate assignment fee to expect? I have a 21 parcel portfolio that the sellers have agreed to $2.75 mil and I have people interested at $3m. Do I write in the assignment at $250k on the info I send them? 
Seller is offering a Seller finance option as well. 
Here is how I have it right now:

PP: $3,000,000

Entry: $450k + CC

Interest: 3.25%

Monthly Payment: $12,000

Balloon: Split Balloon- one partner wants out

in 3 years the other at year 10.
Loan: $2,550,000