I have a signed APA for a solid eCommerce company. $3.5 MM price, $1 MM EBITDA. I have a bank that will loan 50%. Seller will finance $250K.

I won't be able to close on this deal due to an unforeseen event in my life. I would like to hand off this deal to someone who can close with certainty. I am willing to assist to get the deal to close and to serve on the board since I have industry experience and will be a valuable advisor. In return, I would like preferred equity. My question is this: does 10% preferred equity sound reasonable? Too little? Too much?