Where did you get that he was making 300-400k working only 23 hours per week?

Most full-time family MDs work around 40 hours per week (8 - 5pm, includes 1-2h lunch break/catch up on notes/lab reports).

300-400k is also pre-overhead and pre-taxes, which will leave them around 175k after tax. This translates to around 15k per month, which is not an exaggeration.