Typically, the STR property tends to be priced at 10x of the annual gross revenue, so let's assume you buy a house for $500k and you can get $50k a year in gross revenue. 

How are you going to acquire 30 houses free & clear?

House hacking by purchasing a duplex, triplex, or single-family home with extra rooms can help you reduce or eliminate housing costs while building equity.

My DP was around $20k and when I sold it I cleared over $200k.Good luck to you and let me know if there's ever anything else you'd like to know about house hacking.

One of the strategies I am strongly considering for my first deal is a multifamily house hack.

Good question - I've been house hacking on this property so your question made me do some math.Currently I rent a one bedroom studio for $1,100 which covers the $899 mortgage but not other expenses.

I just had a tenant that tried to rent one of my houses and YTD income in September was bigger that YTD income in December.

I noticed you are interested in house hacking. 

I had a house where it was taking so long (9mos) I just sold the place to get out from under the small loan.

The main house(first and second floor) is in reasonably good shape for a home of this era - most of the original woodwork, flooring and tiling looks good.