And it's possible their houses might be underwater or one of the two head of households lost their job?

Mostly blue-collar service workers w/ 2 adult income earners per household.

Hello Everyone,I am about to close on a 1 bedroom condominium and I got a letter from the seller saying that a company wants to De-Convert the building (consisting of multiple condos) into an apartment.

If you want to base your "investing" around something that violates a condominium's bylaws and city and state law , good luck to you.

Even look at condominium associations, some have just a few closings a year but they define the sales date for that development for the year, so it's all in the parameters.

Big Bear was a vacation rental area LONG before AirBnB was a household name. 

Folsom:https://www.census.gov/quickfacts/folsomcitycaliforniaEl Dorado Hills:https://www.census.gov/quickfacts/eldoradohillscdpcaliforniaElk Grove:https://www.census.gov/quickfacts/elkgrovecitycalifornia2019 Estimated Population:Elk Grove 174,775Folsom 81,3282010 Census El Dorado Hills 42,108Median Household Income:El Dorado Hills $137,726Folsom $114,405Elk Grove $93,780Education- Bachelor’s Degree of Higher Percent of Persons age 25+El Dorado Hills 55.1%Folsom 51.2%Elk Grove 36.9%Then there’s WalletHub 2018 rankings:Folsom #1 best place to raise a family in California El Dorado Hills #4 best place to raise a family in California Folsom #1 most affordable housing in California El Dorado Hills #2 most affordable housing in California El Dorado Hills #1 highest family income (adjusted for cost of living) in California Folsom #2 highest median family income (adjusted for cost of living) in California

That’s my opinion, here are the numbers with US Census data as my source:Elk Grove 2019 population: 174,775Folsom 2019 population: 81,328Elk Grove population percent change 2010 - 2019: 14.2% 153,015 in 2010Folsom population percent change 2010 - 2019: 12.7% 72,203 in 2010Elk Grove median value of owner occupied housing units 2015 - 2019: $406,300Folsom median value of owner occupied housing units 2015 - 2019: $524,100Elk Grove population per square mile: 3.626Folsom population per square mile: 3,290Elk Grove bachelor’s degree or higher: 36.9%Folsom bachelor’s degree or higher: 51.2%Elk Grove’s median household income 2015-2019 in 2019 dollars: $93,780Folsom’s median household income 2015-2019 in 2019 dollars: $114,405As for Tracy, I can’t speak to where you would like to live and how it will or will not meet your expectations.

My budget doesn't allow me to buy a house or a condominium so I might have to go with co-op.

There are programs for low income households to help pay for utilities.