I have costs in column A, that I want to mark up and multiply by a factor of
2 or 3 in varying cases. However I want to the result to end with .99 cents
as opposed to whatever change it will be i.e.

A B C
costs price formula desired price
16.50 =3*A3 49.99
13.50 =3*A4 40.99

Any ideas, I thought something along the lines fo the ceiling function would
work, but I am not certain.

Any help is appreciated thanks