$16000 - yes that is excessive. How many hours per year do they estimate your portfolio will require.
That would be 160 hours @$1oo, or 80 hours at $200.
Nearly all the admin work should cost no more than $100 PA, so that is a big chunk of advice, each and every year.
It may represent good value to you, if you feel that they can offer some magic pudding, that less expensive finance advisors do not offer.
The only advisor that I can think of that would charge these sorts of fees, are the ones who charge a % of funds being managed. So at 1%, on a $1.6m fund $16k would be the go. If so, then negotiate a top charge that you feel is reasonable.
Q - if it is a 1% deal and you had $10m, would you be happy with paying $100k each and every year?