All you really need to start selling weed is your brain, your gut and some weed to sell. However, it becomes complicated and inconvenient if you don't have an accurate way of measuring or something to put the weed in (i.e. baggies). Baggies, obviously, are cheap, but a good scale is not. You can buy cheap balance or spring scales at headshops or online for less than $30 and often less than $10 but they're not accurate enough, they don't last very long, and they're difficult to use. One of these cheap alternatives might be good for you if you don't know if you really want to get into the business long term, or if you just want to approximate the sacks and aren't in it for the money.

A good scale, like these two examples, will run over $100, but if you treat it right it should be accurate for years to come. Small digital scales like these jewelry scales will only weigh accurately to a couple ounces.

A triple beam scale is also an option, though they are larger and more difficult to use, they are just as accurate as a digital scale at small weights but remain accurate up to a pound or more (just in case you plan on working your way to the big time).

To test a scale for accuracy, use a clean, unblemished nickel, which should weigh out to 5.0 or 5.1 grams. A penny should weigh exactly 2.5 grams. Dollar bills are an even gram.

Whatever you do, don't steal a scale from your school's science department. That fucks over your fellow students. Plus, if you're caught, most school officials are smart enough to figure out why you were stealing it.

If you have no access to a scale, you have the option of eyeballing the sacks straight from your stash, which I don't recommend, unless you just don't give a shit, or are really good at guessing weights. The advantage to eyeballing all your sacks every time is that you neither have a scale nor pre-weighed sacks in your possession, and if you are busted with less than a couple ounces all in one sack, it's difficult for the police to prove you were selling it.

Another option, of course, is to use your dealer's scale at the time that you buy your supply. This brings up the issue of carrying around a pocket full of weighed bags, which of course is riskier than having it all in one bag, because if you're caught, it's easier for the police to show that you intended to sell it. If your dealer is willing to deliver the weed to your house and bring a scale to let you use, this is the ideal situation.

Another option is to buy a weighed ounce (it's best to watch the person weigh it out), then simply break it into eight equal parts, getting a friend to help make sure they're all even. They won't be perfect, but it will all average out in the end. You won't rip anyone off and you won't lose out yourself.

You can probably figure out some alternative if you don't have any baggies. I've seen many people use cellophane from a cigarette pack, melted closed with a lighter. Or you can make all your customers bring their own containers. That's better for the environment anyway.

Another useful piece of equipment is a safe. However, this is not an investment to make right away. Not until you're confident that you know what you're doing. A good safe can run a few hundred dollars, and a fire-proof one costs significantly more. I had a simple lock-box at one point, but someone still broke into my house and pried it open with a screwdriver. So after that I bought a real safe. But until then, just hide your stash well, and don't let anyone see where you put it.

On the other hand, if you're that worried about your customers, friends or roommates stealing from you, maybe you need to change your situation.