Surprise in this scenario means it pops up annually, rather than monthly/quarterly.

@Erwin Groenendijk, you are correct but Americans should be able to credit their taxes paid in Spain against their equivalent US taxes courtesy of the treaty for the avoidance of double taxation between the two countries.

(Check out the "'Questions on Household Definition" about a quarter of the way down.)

Regardless, our goal is to keep pushing forward and do at least one deal every quarter.

I just set up my solo 401k, and the LLC that will be 100% owned by the 401k, and ready to buy real estate using the LLC.My question is regarding taxation.

As always, the most detailed and complete answer from "The Black Belt in Real Estate Taxation".That's exactly how I imagined it worked. 

The fact that article came out in 2001 and that hasn’t happened yet nearly a quarter of a century later literally just proves my point.

I know regulations change almost by the quarter so what is true now is probably different last year. 

We're also able to evaluate our rates, and keep pace with inflation, on a monthly and quarterly basis because of shorter term leases.Now we syndicate larger self-storage deals and work with passive investors.

You might want to create a list of 50-100 prospective properties that meet your criteria using a tool like PropStream, optimize it, and then market to that list up to 30 times a quarter.