I'd imagine that the cellular provider would be seeking to improve the infrastructure in the particular area first?

I owned a heating and air company with my husband for over 22 years and I can tell you there are enough losers out there that will pull nonsense like not showing or giving outrageous prices.

The property value has been improving nicely for me, so I was thinking of selling it to lock in the profit (trying to time the market :D ).

Perfect prey for gurus, except this group usually lacks money they can take from them.Move up the age spectrum, young adults, much like the younger group but they are more mature, judgment has improved but generally we are still rather naive and trusting.

Are there any other improvements on the property like fencing, grading, roads, etc.?

If you add it to your balance sheet to improve your net worth then, again, that is not profit.  

HEATING AIR: Boiler in basement that services all units, making heat included in rent. 

You can smell the air, make connections (thoughts and people), get additional ideas, and discover more neighborhoods.

While it's just as possible that rates could improve tomorrow (after all, if lenders already "knew" that rates were going higher, they wouldn't be wasting their time offering you lower rates today), the classic lock/float quip applies: it's better to lock when you should have floated than to float when you should have locked.

But if you pay attention to where the local government is spending money you may be able to purchase if an area that  will be much improved later.