If by "current market value" you mean this instant, then yes it is a bit overvalued, but mostly it just isn't that stable. On several occasions in the past week and even in the past 24 hours, the price has dropped to $1 and the stabilizer has stopped selling (and has even done a tiny bit of buying).
Realistically we can't make changes like the interest rate on an instantaneous basis and need to make a longer term assessment.
Also, when HBD is overvalued I don't believe the interest rate serves as much of an incentive to hold it (of course it does somewhat) for the simple reason that anyone buying or holding at more than a 5-10% premium is clearly speculating, and stands to make or lose a lot more than the interest. In that case, paying it is probably a little wasteful but likely not all that effective or harmful in terms of price action. It's more effective as an incentive to hold when the price is at or near $1 (interest serves as upside and downside is limited).
That is why I said that I have "some disagreement". Overall I don't think that it makes much of a difference in terms of price action. I would even go as far as to say that having a much higher APR (10% to 20%) is not a bad idea in the long term. Well...maybe 20% is too high (or maybe not).
Agree on all points