"Swapping" Home Titles: Questions and Maximizing Tax Efficiency

[Jeffrey L Jerschina]

My wife and I intend on moving to rural coastal Oregon in a few years. We're looking at buying my neighbor's in-laws property. She's an older woman (we'll call her Jane) and lives comfortably in a trailer with some pets and an elderly roommate on 5 acres of land.

My father in law owns an investment property on the coast, about a half acre of land, that he bought in 2007 at the peak of the bubble. Jane is interested in trading her very desirable property for the investment property on the coast (desirable as in if she posted it for sale, plenty of offers from locals and 'city' folk.) 

The properties haven't been appraised in some time. The tax assessment in my FIL's investment property is 148k, and the assessment on Jane's property is 131k. Jane's property has a trailer, but a few ancillary structures and newer septic + great water system. Both properties are paid off in full. The investment property needs some repairs (about 8-10k). The real values of both properties are much higher, and there's some details left out for brevity's sake that I can add in response to comments. 

The question: what is the most tax efficient way to 'swap' properties? 

Is it to sell each other the properties at a number between the tax assessment values? For 10$? Would the best help to go to be a CPA with real estate expertise or a real estate attorney?

Thanks for reading my little tale of adventure, and I'm happy to clarify or elaborate!