RE: Calculating the USD Vote Value for a Hive account

I think this discrepancy comes from two things:

Please note that my code by default calculates the Vote Value as if you had 100% Voting Power.

If you want to check your CURRENT vote value, with the Voting Power that you have at the moment, use getUserVoteValue({ username: 'cryptosharon', fullVotingPower: false }).
As far as I understand, most of the services do not follow the formula from the documentation. The formula clearly specifies to provide the base price from the condenser_api.get_current_median_history_price call:

Last thing we will need is rate of the get_current_median_history_price, returns median price rate bucket with base element.

If you check the response from that API call, it is currently base: "0.894 HBD". That's what I use to calculate, but I find that if I provide 1.0 as the base value, and not that value, the estimated values will be much closer to the ones given by services such as PeakD or hivestats.io. I don't know why that is, though, that those services do it differently than it is in the documentation.