Selling a junky house and buying one with two houses on one lot can offer several benefits, both financially and practically. Here are some of the key advantages:

1. Income potential: Having two houses on one lot means you can rent out one or both of the properties for additional income. This can be a great way to offset mortgage payments or generate passive income.

2. Multigenerational living: Two houses on one lot can provide a solution for families who want to live together but still maintain separate living spaces. This can be especially useful for caring for elderly parents or adult children who need their own space.

3. Investment opportunity: Buying a property with two houses on one lot can be a smart investment, as the value of the property can increase over time, especially if the location is desirable.

4. Flexibility: Having two houses on one lot can give you the flexibility to use one property as a guest house or office space, or to accommodate different living arrangements as your family's needs change over time.

Overall, selling a junky house and buying a property with two houses on one lot can provide several benefits, from additional income potential to more flexible living arrangements. As with any real estate investment, it's important to do your research and work with a trusted real estate agent to find the right property for your needs and budget.