When to use seller financing as a seller

[Pope Lake]

BP, when would be the best time as a seller, to use seller financing?

I know that one of the reasons some do it is potentially at the end of their career and want to avoid capital gains taxes. But aren't capital gains taxes applied whenever you don't do a 1031 exchange in REI - or when the money isn't reinvested?

In this sense, my question is two-fold. Thank you!

[Joe Villeneuve]

Instead of looking at this as a way of avoiding something, let's look at it as a way of gaining something.

First, let's assume that the property in question has been paid off (maybe for some time now), and the REI has been enjoying the heightened cash flow that comes along with it. Let's also assume that the property has appreciated quite a bit since it was first bought (maybe more than 30 years ago).

Now, if the new buyer is an investor looking to continue to use this property as a rental, asking full price for this property probably won't fly...it won't cash flow for the new REI. However, the seller doesn't need to ask full price...if they accept a form of Seller Financing.

Here's an example: 
1 - Property Value = $150k, 100% equity, current cash flow to Seller = $1000/month with no debt.
2 - If property sold to new buyer/REI at $150k, there would be negative cash flow...so why bother?
3 - Instead, Seller sells to new REI using Seller Financing at $120k; 7 yr balloon with 6% Simple interest only payments
4 - New REI/owner/buyer can now cash flow property
5 - Seller makes more than the $150k in total with the added interest...and, the interest only payments are higher than the cash flow they were getting to begin with.