Can anyone help me? I doing the price, there is two processes, first I have
to calculate the USD to my country's currency then I have to round up or down
the price. I need the price end with 500, 700, or 900 without decimal.

The way to round the price is like this.

0-299 round down to 900 ex: 3250 round to 2900
300-599 round to 500 ex: 4365 round to 4500 if 5580 round to 5500
600-700 round to 700 ex: 8600 round to 8700
799-900 round to 900 ex: 4800 round to 4900
901-000 round to 900 ex: 3980 round to 3900

thank you in advance