A: I do not believe underwear would fetch sufficient funds to underwrite a decent home gym.
B: Some homes, admittedly nice homes for normal inhabitants, do not have room for a squat rack, much less a ceiling to floor power rack.
C. As much as I love the sentiment that your health is your wealth, sadly for many of us our health is damn near all we have period. THere is no spending for weights in the budget. If you can indulge in that way yourself, keep your tongue in your mouth until you have walked a mile in someone else's boots, someone less fortunate than yourself in particular.
That said, some serious workouts can be had with body weight squats, home implements, thera' bands, etc.
No disrespect intended, just saying, all are not created equal except in the eyes of the lord.