HELOCs are a great way to participate in real estate because they offer inexpensive access to very liquid funds. 

The condo can get about $900/month in rent and the home $850/month yet the SFH sees $2200 less per year in expenses.

When I get rid of one that still has life in it, I give it away on Craigslist).There are plenty of inexpensive, very well-reviewed mattresses that are available - just do a little searching, you'll find them for ~$300-400.  

I’m trying to decide between Allure flooring and an inexpensive engineered hardwood at around the same price.   

Specifically I thought about how maintenance and repairs for an apartment in an expensive market like SF is not going to be proportionally higher than in an inexpensive market like Omaha.

If you cannot buy it so inexpensively that you can easily double your money tomorrow, don't buy it.

When you're buying smaller units, often times you just have to figure out what the market is at and what you should be paying in expenses due to poor recordkeeping.

We try to make the units appear very high end using inexpensive materials where we can.

All of that will rack up $2k to $3k in expenses.

Thanks,HannahHannah,My suggestion would be to try to find an inexpensive in-class course with a compressed schedule.