The difference was never close to 10% nationwide, it never could be with land,labor,transportation,regulation and material difference. 

I've also been looking at major road projects to see what the Dept of Transportation in my state is up to.

While proximity and transportation costs are certainly valid concerns, it's crucial to also assess the overall market conditions and potential profitability in each location.You mentioned that the market in Vegas doesn't seem to be doing well at the moment.

I'm guessing cash flow properties might be hard to find in Boston as well.

Well, since you delegate dishwashing to your dishwasher, clothes washing to your clothes washer, feather waving to your air conditioner, transportation to your car, hauling ice to your refrigerator, cutting your lawn to your gardener, growing your food to your grocery store, shearing your sheep & weaving your clothes to the clothing store, and so on, it seems to me that you don’t have anything to do with your time already. 

Now rates are falling, more buyers are coming back from the sidelines, my guess is we might have a hot spring market.PS: when you look at the chart below you can see that markets with a colder winter have a more pronounced seasonality (Boston vs LA)

The transporter/mule is not having a good day...

Look for areas with good growth potential, low crime rates, proximity to amenities (schools, shopping centers, public transportation), and potential for rental demand.

Offer transportation free from commute area to where he works where housing is cheaper.

Offer to pay to have movers transport the "valuables" to a storage unit and pay the first few months so the seller can have time to sort through it.