Bruce wrote...
How can I round prices to the nearest 0.05 or 0.09?

Eg 1
5.01 to 4.99
Eg 2
4.44 to 4.45

to 0.09: =ROUND($A10+0.011,1)-0.01

to 0.05: =ROUND($A10+0.051,1)-0.05

or

to 0.09: =ROUND($A10+0.009,1)-0.01

to 0.05: =ROUND($A10+0.049,1)-0.05

depending on whether you want to round, e.g., 5.04 up to 5.09 or down
to 4.99.