round numbers so the total is divisible by 5

HI
I have the round function set with 2 decimal places on a currenty field in
an Access table. This field calculates quantity x cost. The cost of an item
could be below $1.00. The quantity could be a whole number (1) or a part of
a whole (.5, 1.3). I need to have the calculation round up to the nearest
number divisible by 5. Ex: 1 x $ .75 should equal $ .75, but my total
calculates as $ .80. If the number is already divisible by 5, I don't want
the number to round up. Other examples a 1.2 x $ .20 ($ .24) should round
to $ .25 OR 1.7 x $ .20 ($ .34) should round to $ .35 OR 1.3 x $ .20 ($ .26)
should round to $ .30.
I don't know anything about writing "code". I do my designing for
calculations only using queries, controls on forms or reports, and macros. I
have played a tiny bit with the modules, but I really don't know what I am
doing in that area.
Can anyone advise me on this rounding issue? Thanks so much.