The next question is though how is the property to be rehabbed and financed. If you are paying cash to purchase it is of little consideration. If you are going to finance the purchase and rehab the $70,000 will for sure require special financing. The property needs to qualify and the condos require special approval that SFRs do not. Have you bee pre approved for a purchase rehab loan? There are many additonal things you need to be prepared for, like contractor approvals, code violations, project managers etc. etc.
If you need direction call me at 708.299.3244 and check out my sites.
If it needs a gut rehab you definitely need to know what you are doing though. It may be a good buy for someone but if you don't know what you are doing you can get in big trouble.
In general I think single family homes over time will appreciate faster than condos in Chicago because there will always be more condos. Its unusual to find new entry level homes in the city (at least not in under 400K range) but condos are built or coverted every day. It's simple supply and demand.
If you want to talk about it more give me a call at 773-244-1110 and we can walk through what needs to be done in the two properties and I can give you a more educated opinion. Best of luck!