For not contributing to 401k option, since we can only contribute $16500/year (idk about 403b), you have to wait a few years to collect this 50k(?) to make 20%. But you have to pay tax for this $16500.
Not sure if I do the math right, but you may be paying $5445/year for that 401k tax (assume that you’re in 33% bracket), versus paying $4800/year for PMI (if it’s 400/month). Number is about the same, no?