I believe it was around the mid 90s when the Nintendo Game Play Counselors hotline became a 900 number. It wasn't horribly expensive, but still something I used sparingly. I called a couple times myself, once to get help in Link's Awakening and another time to ask about the glitched up shrine in Lufia 2 (which they didn't know anything about and just suggested that my copy of the game was defective; I brute forced my way through the area, which isn't terribly hard to do, and years later learned all US copies of the game are glitched in that manner, so it wouldn't have helped to return my copy and get another). Around that same time, they put up a pre-recorded line where you could get tips on a couple dozen games, whatever was big at the time. That line was free (might've been long-distance, though).

Prior to the 900 number, the counselor hotline was just a regular number with a Seattle-region area code (206), so it was free for those who lived close to Nintendo of America, which is in Redmond, WA, but long-distance for everybody else. I kind of got skunked on it myself because I lived in Washington state, and my city had the 206 area code when I was a kid. But I didn't know about the hotline at that point and didn't take advantage of free calls. By the time I was interested in calling the hotline, the region that the 206 area code applied to was shrunk down, and phone numbers in my city got a new area code. So then it was long-distance for me too, and the switch to the 900 number came shortly thereafter.