I always hate filler episodes when you already know what's going to happen because if the plot element played out successfully , it would involve either the show ending/ being cancelled or major characters being dropped , and the show retooled. This is the case with the Evans trying to buy a house in this episode. Let's forget that they barely can come up with the down payment let alone the other costs that would be involved since this is the fantasy world of TV.
The major thing is if they had gotten the house , that would mean a change of location out of the ghetto so to speak which would leave the characters of Wilona . Penny and Bookman back at the Cabrini Green projects hence they'd have to drop those characters since you wouldn't need them because the Evans no longer would live there . In fact, the show probably should have ended with this episode instead of waiting several episodes later with the end of the rainbow as imo the characters were getting too old to be living with mom - Jj was like in his late 20's and Michael was 18 or 19 and Thelma in her late 20's and married.