Phobos is right about the rules saying no price discussion here in this subforum.
Maybe the OP isn't talking about an actual gram of 99.9% lab grade fentanyl but is instead talking about a gram of powder from the streets where it's got fentanyl or a fentanyl analogue in it but it's been cut to where it is - ballpark - about the strength of street heroin. This kind of confusion isn't that uncommon, most people these days already know their "heroin" actually contains fentanyl, so some will mistakenly say something like "I am using 1 gram of fentanyl a day" when they really mean "I am using 1 gram of powder a day that happens to contain a small unknown amount of fentanyl"