There are several pros and cons to purchasing real estate in the city of DeKalb, Illinois:

Pros:
1. Affordable housing: Compared to many cities in Illinois, DeKalb has relatively affordable housing prices.
2. Strong rental market: With Northern Illinois University located in DeKalb, there is a strong rental market in the city.
3. Community events: DeKalb is known for its annual Corn Fest, as well as other community events throughout the year.
4. Good schools: The DeKalb School District has received high rankings and offers a variety of educational opportunities.
5. Access to recreation: There are many parks, trails, and other outdoor recreational opportunities in and around DeKalb.

Cons:
1. Limited job opportunities: DeKalb has a relatively small job market, with limited opportunities for high-paying jobs.
2. Non-diverse economy: The economy of DeKalb is focused largely on education and healthcare, which could make it vulnerable to economic cycles.
3. Severe weather: Like other parts of Illinois, DeKalb can experience severe weather, including tornadoes and winter storms.
4. Crime: Some areas of DeKalb have higher crime rates than other parts of the city, which could impact property values and safety.
5. Noise and traffic: Being home to Northern Illinois University, there can be a lot of traffic and noise from students and campus events.

It's important to consider all of these factors when deciding whether to purchase real estate in DeKalb, or any other city. It may be helpful to work with a local real estate agent who can provide more insights into the specific neighborhoods and help you make an informed decision.