if it's so hard for you to consider opportunity costs when budgeting (a trait unfortunately shared by most humans), this seems like it could be easily fixed by

if it's so hard for you to consider opportunity costs when budgeting (a trait unfortunately shared by most humans), this seems like it could be easily fixed by putting the money you save into a discretionary spending account, to be used for renting hotel rooms for friends, or rideshares, or any such "unnecessary expenses". if your original assumption that buying a smaller house or whatever saves money, then this account should still increase in value every year, which can be rolled over into general savings. by keeping the money in a separate account, you can feel free to spend it on things that would otherwise be "free".