Other methods have been discussed. For example, mods could be crippled. DBM didn't exist back then, and the other boss that did that I don't remember the name of, didn't do as much back then as DBM does now. If our goal is to recreate the experience as it was, then obviously not having DBM would be a reasonable way to accomplish that. DBM simply existing, makes the game today easier than it was. So disallow it. Again, this is completely consistent with the spirit of vanilla. Remember one-button-decursing? That was nerfed. They crippled the capabilities of the modding API to disallow that because it made the game too easy. So what if they cripple it a little bit more to once again make the game less easy?
Logging in for the first time, being welcomed by THAT login screen and THAT music... You can't not be taken back if you've played Vanilla, and especially if you've played 2 years of it non-stop all day every day. I probably stayed 10 minutes in character creation just because of the music alone (and trying to get my character looking exactly as it did back then - although I wasn't a shaman then). The whole intro experience was especially amazing for me since the Tauren starting zone was my first encounter with WoW in the EU beta, and a little bit of that spark did return. But is that all Classic has to offer? A trip back in time when we were wowed by the game for the very first time?
Where to get materials and reagents you may ask? Buy for cheap off farmers in bulk or track Auction House lots. Get in touch with most big sellers. Communication is important here, send a whisper or write them a letter. It would be good for both of you to establish business relationships. Constant suppliers and buyers is convenient for both parties to save the time and effort.