I agree with @James Wachob for the most part. You have to do lots of these to make any real money but it's apples to apples. It's the same philosophy as why investors buy multi unit buildings. If you have a vacancy on a 100K SFR you lose 100% of your income. If you have a vacancy in one of your 25K houses (that are all on the same street) you still have 75% of your income. Either scenario you still spent 100K so it's not like having a bunch is an issue. Nobody dreams of owning 1 or 2 rentals and calling it quits. Let's say they did... they spent 200K and got 2 houses. That seems risky to me (all your eggs in 2 baskets and liquidity is basically all or nothing) or buy 8 25K houses that will generate more rental income than the 2 "nicer" houses.
Typical Example In my area
100K house 3/2 in C neighborhood rents for about 1000/m. Total rent = 2K/m
or
Same house plan in D neighborhood worth 25K rents for 650/m x 8 = 5200/m and diversity
Even if you assume that your repairs are going to be higher (I would argue they are similar because I'm not using high end materials due to less picky tenants) most property managers will give discounts for having more units under management so my expenses actually get lower the more I buy. If I need quick cash I now have multiple properties that I can offer to a turnkey provider or hedge fund buyer that wants the "pig" and they will do it because there is no Cap X in the near future because of how I just did a complete rehab in the last 5 years or so.
Doing this type of strategy does a couple of things.
1. Even if the market as a whole doesn't have much appreciation I probably forced a little value add simply by rehabbing an entire street which raised my rents and community value.
2. I got 5 years worth of depreciation on my taxes which nobody calculates as income
3. My pig paid for itself in that 5 yr time because of higher ROI which now gives me options
4. If I want to sell to my tenant on land contract for top dollar I can because he doesn't qualify for traditional financing where the guy paying 1000/m probably does
5. My rent is guaranteed through subsidy, inspections are easy, the other isn't
I can rattle more off but you get the idea. It's all relative. I don't believe anyone should be a slum lord but if you believe you spend the same amount for same quality you are asking to lose money and this is where most go wrong IMO. C class tenants DEMAND central air, garages, and landscaping. My tenants WANT window units, off street parking, and left alone. With the rising demand for low income housing because the majority of investors (evidence by threads on BP) are shying away from these types of houses I have tenants trying to convince me to choose them but you all are fighting to find that perfect tenant to choose you....please keep fighting over the "GOOD DEALS" - I'LL GLADLY TAKE WHAT YOU DON'T WANT