My suggestion is shrooms. My reasons are:
1.) Psilocybin mushrooms are easier to procure than, say, 4-aco-met, 4-ho-met, 4-aco-dmt, because it's a fungus and grows in nature in practically every geographic area and ecosystem.
2.) They aren't illegal to gather from one's backyard or grow (laws vary between jurisdictions, so please take that into account, lest you end up cuffed and incarcerated).
3.) Psilocybin/psilocin is among the best tryptamines available. Five
grams of dried 'shroom taken in silent darkness (Terence McKenna' s so-called 'Heroic Dose') offers a taste—nay, a buffet—of what tryptamines have the potential to offer, and as well or better than most other tryptamines.
4.) You don't have to worry about the quality, potential adulterants, or if the drug is what it's really what you were told it would be (e.g., not some other drug or substance). Mushrooms aren't terribly easy to confuse with something else or to adulterate, unlike, say, a white crystalline material.
5.) They're free if you procure them in the wild, and vastly inexpensive—gram for gram—relative to other tryptamines only available online or from gray-market drug purveyors.
6.) Less than $200USD is more than enough to grow pounds of these fungi in your closet or basement. Whereas $200USD might get you only a couple 50¢ coin-sized baggies of a fraction of a gram—a dozen doses at most for a majority of tryptamines—if you're lucky.
7.) Because they're easily and cheaply grown, you don't have to rely on shady middlemen or unscrupulous intermediaries and pay their prohibitive fees.
8.) They are as toxic as marijuana. The lethal dose is simply not practical to reach. Whereas many other tryptamines are measured in micrograms or milligrams and have lower LD50s, thus making a slight miscalculation result in a dose many times greater than the lethal amount.
I could enumerate many more reasons why 'shrooms are the way to go; these are just the most essential