Inspection on an As-Is Duplex

[Parag D.]

I am looking at a duplex near a university that is rented to a bunch of college kids till July of next year. The house is old (50-70 years old) and the owner is selling it as-is. In such situations do we still do an inspection before putting offer? I am mainly concerned of bigger expenses like roof, furnace, water heater or structural issues etc. 

Not sure if it helps to spend the money upfront in inspection or to account for worse case scenario and put the offer. As the owner is not going to make any repairs based on inspection report, wasn't sure if the inspection still needs to happen prior to the offer.

Thanks in advance. 

Parag