If you offer more $ for the property than the all cash offers AND you appear to the seller to be highly qualified in the method you are using for sourcing the payment, at some point your offer will be more appealing than the all cash offers.I don't understand why you would consider a 1031 for another property in two years. 

There are a million spammers now just asking for seller finance on anything.

I have found sellers often place priority on seriousness. - Post closing Plan.

There's a few different ways to focus on a lower rate such as with house hacking and making the investment your primary residence, requesting a significant closing credit from the sellers for standard rate buy-downs (which I've had great success with recently), or utilizing lenders who offer short term rate lowering solutions such as 2-1 rate buy downs (again, ideally paid for by the sellers).

Since it's rare to find a buyer, the agreement expires and you have a willing seller to negotiate a deal with. 

Supply and Demand: When buyers outnumber sellers, prices and rents rise.Population Growth: Cities with significant and sustained population increases are more likely to see long-term rent growth.Job Stability and GrowthA property’s value is tied to the jobs in the area.

Cost per lead (CPL) is crucial—it shows how much you're paying to get a potential seller or buyer’s info, and you want this as low as possible without sacrificing quality.

Quote from @Chris Seveney: I wonder what the OP's true motivation is for asking this question. 

The seller wanted to purchase another home with the proceeds from the sale of this one.

I would focus on coaching that helps you become a local expert and build relationships with sellers, not try all the BS marketing techniques.