Operating Expense Ratio is how much is costs to run, or operate, the property. The rule of thumb is 50%.
@John Warren is saying that if they are saying that it costs less than 45% of the gross income, then they're cooking the books.
For example, 5317 N Hoyne Ave says their gross income is ~$173k; 45% of that is ~$78k. Expect to pay ~$70-85k in expenses.
To dig just 1 layer deeper I'll tell you this.. they say their water is $4,651/year, which can't possibly be true. I have a 4 unit that runs ~$300/month ($3,600/year) and I think there's a leak somewhere. My 5 unit is ~$250/month ($3k/year). There's no way a 26 unit is $4,651.
These aren't your friends, they're trying to sell to the highest bidder. I will tell you this, with the larger apartments, the big whales have already gone through the meaty stuff and you're left with the scraps. You're a big fish in an ocean of whales and sharks.
I've found it's better to be a big fish in a small pond. There's nothing wrong with multiple 3-4 units where you hold negotiating power over the smaller fish. The expenses may be slightly higher because of economies of scale yet the opportunity to diversify locations (as well as diversification of investments) is well worth it, in my opinion. Also worth mentioning that you are much more liquid because it's a magnitude easier to sell one or two 3-4 units than a single behemoth you linked.
