Just FYI-not all these boom towns are equal but there still is great opportunity if you do it right.

My assumption was similar to Steven's, that since the cost of rent is equal to room and board for the university, this cost could qualify.

$4000 sell price, less $1320 purchase, less $1250 commission equals $1430 net profit (not $2128) - not sure where the $70 came in. 

If your home remains your main home, you are required to repay the credit in equal payments over 15 years with no interest charges.

An eviction + tenant not paying rent + damages can equal $5k - 10k real quick.

I would say focus on hitting the 50% rule (expenses equal to 50% gross rents after vacancy assumption).

If the thing is worth $40,000, for example, all things being equal you should be able to refinance it at 70% LTV, or $28,000.

Assessed value does not equal appraised value.

For example, if SFR in the nearby town are selling for $210k and properties with similar characteristics are selling for $185k, then (if all other factors are equal), the locational adjustment is -12%.You can then take your MF comparables from that town and apply the locational adjustment after adjusting for all other factors of difference.

The easiest way to do that would be to get estimates from contractors on your first couple of houses, make a note of what repairs cost approximately how much, then figure out how much per sf. that equals out to.