My pricehist command that used to fetch prices from Yahoo Finance stopped working ("unauthorized"), and I found this 6-month-old reddit thread suggesting it's now a premium feature:
https://www.reddit.com/r/excel/comments/1crgtaw/unable_to_copy_yahoo_finance_data_anymore
FYI, or please let me know if you can still download prices from them, especially with pricehist.
And a followup question, do you know of another pricehist price source that provides prices for things like Vanguard bonds ?