If you have a small crafting business, you've likely considered buying a heat press. These machines consist of a base and two plates. You place your product between the plates, close, then let the heat and pressure adhere the iron-on to your item.
Large work surface
Heat and pressure make results last longer and adhere better than an iron
Not as portable as the other options
Since both plates are heated, you would have to be extra careful not to be burned.
Most expensive on average between the three options