Remove the worst paper / label
Remove as much of the price tag as possible, so the oil can soak into the glue best possible.
Lots of oil
Then oil: Put oil on the glue and preferably so much, that it can soak in it. If it is on a surface where the oil will glide off, you can use a cotton ball / other paper with lots of oil on it and put it on top. Let it be for at least an hour depending on the stubbornness.
Rub and scrape a little and the glue comes off as in a Vanish advertisement.