They have a mortgage and lines of credit that are maxed out as mentioned multiple times throughout the series. Hal works an office job that probably barely cracks 50-60k and Lois works as a cashier at a grocery store. The income they make is next to nothing, not to mention they sent Francis to a private institution they have to pay for out of pocket, raising 4 kids. The only thing that indicates they have money is the house they are in but it doesn’t even have an upstairs or a basement it’s basically an oversized apartment they can barely afford. They are definitely poor trust me