It really depends.   

As far as being expensive; if the tax liability is not large enough then yes I agree, however, it depends on what is being sold too.

Leverage / down payment required will depend on if you're a U.S. citizen, Green card holder or if you have another immigration status. 

Focus on one or two target markets, get familiar with the numbers, and use tools like BP calculators to analyze potential properties.Whether you start now or after graduation depends on your bandwidth, just have the right systems and support in place first.

It probably depends on the rent. 

It is really going to depend on your cash position and long term goals.

but, it's not going to be "profitable" for several years, depending on how you define profit.you'll have a down payment, then closing costs - which new investors always seem to be shocked by - then potentially some costs to get a property rent ready, then you'll pay a month's rent to get it listed and rented out, then you'll likely have some repairs after the tenant moves in.  

But the likelihood of success with that depends on the specific street.

Hi Paul, it all depends on your comfort level. 

I found that it is highly dependent on location and secondarily on time of year.