If you want the lowest cost per milligram of THC, buy a 510-thread cartridge and a rechargeable battery instead of a sealed disposable pen. That is the pick. Everything after it is a trade between convenience and price. Four criteria decide which format is cheaper for the way you use cannabis: hardware cost, cost per milligram of THC, oil lost to clogs and dead batteries, and how your state taxes the purchase at retail. Skip the sticker price comparison and do the per-milligram math, because a cheap pen with weak oil can cost more than a cartridge that looks expensive.
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What to compare before you look at shelf price
- Cost per milligram of THC. Divide the package price by the total THC milligrams printed on the label, then add tax. A 1 gram cartridge and a 0.5 gram pen are not comparable until you do this.
- Hardware. A 510 battery is a one-time purchase you recharge and reuse. A disposable pen builds a battery, a coil, and a plastic shell into every single purchase.
- Oil loss. Disposables get thrown away with oil still sitting in the wick. Reusable carts can be drained or refilled, so less of what you paid for is wasted.
- Taxes. Retail cannabis in legal states usually carries excise tax plus ordinary sales tax, and both are calculated on the retail price of the whole item.
- Potency and testing. State-mandated lab testing adds cost per batch, which hits small runs of cartridges harder than bulk flower.
Top pick: 510-thread cartridge with a rechargeable battery
Best cost per milligram for anyone who vapes more than occasionally, and the format with the widest brand and potency selection on a dispensary menu.
Cannabis Pen vs Cart Review: Which is Best for You?
Pros
- The battery is bought once. Every later purchase is oil only.
- Cartridges come in 0.5 gram and 1 gram sizes, and the larger size usually drops the cost per milligram.
- You control voltage, so you can run lower heat, waste less oil, and stretch the cart.
- Hardware is compatible across brands, so you can chase sales.
Cons
- Higher upfront spend because the battery and the cart come in the same trip.
- Batteries get lost, and cheap ones die early.
- Clogging and leaking happen, mostly with thinner oils.
Buy this if you vape weekly or more and want the lowest price per milligram over a month.
should i buy a cannabis pen or cart
Runner-up: All-in-one disposable pen
Highest upfront convenience, worst long-run cost per milligram.
Pros
- No charging, no threading, no settings. Draw and go.
- Good for travel and for testing a strain before committing to a full gram.
- Lowest single purchase price on most menus.
Cons
- You pay for a battery, coil, and shell with every unit.
- Fixed voltage, so hot hits burn oil you already paid for.
- No recharge means the pen dies with oil still inside.
Buy this if you vape a few times a month, want zero hardware, or need something that fits in a pocket with no charger.
Third option: Closed pod systems
Pods sit between the two. The battery is reusable, but the pods are proprietary to one brand.
Pros
- Reusable battery, so you only re-buy the oil.
- Snap-in pods avoid the threading problems that kill 510 carts.
- Consistent draw and temperature set by the maker.
Cons
- You are locked into one brand and its price, so no shopping sales across labels.
- Pod sizes tend to be small, which raises cost per milligram.
- If the brand leaves the market, the battery becomes scrap.
Buy this if you found one brand whose oil you actually like and you value a clean, consistent hit over the cheapest possible gram.
Costs that get left out of the comparison
- Replacement batteries, chargers, and money spent on pens that die early.
- Clogged carts, which are pure loss because the oil sits inside a sealed unit.
- Excise and sales tax, which apply to the entire retail price, not just the oil.
- Potency variance. A cart labeled lower in total THC costs more per milligram even at a lower shelf price.
- Loyalty discounts. A dispensary deal on a 1 gram cart can beat a cheap disposable by a wide margin.
Which one to buy
- Daily or weekly vaper: 510 cartridge plus a battery you replace about once a year. Lowest cost per milligram.
- Light, occasional vaper: disposable pen. You are buying convenience, and the math stays close at low volume.
- Brand loyalist: closed pod system, if the pods come in a size that keeps the per-milligram cost sane.
- Budget focused: buy the largest cartridge your battery handles, wait for a sale, and check total THC milligrams on the label before you pay.