You may find yourself plugging and unplugging. Also, if you are using a dial-up connection, getting online to buy postage and stamp an envelope can be a hassle. Definitely consider an offline product if you have a dial-up modem. Pricing Specific pricing for each vendor is listed above, but don't forget about the add-ons, which can certainly add up. Each provider structures its pricing a little differently.
Itemized costs can include a startup fee, a monthly fee, equipment charges, and postage surcharges.
Some vendors do charge additional fees - make sure you look into it before making a decision. And don't forget consumables, which you should always figure into your ongoing costs. You may even need to purchase a thermal printer and postage scale. Payment methods for the actual service also vary. At this point, all take credit cards and many now have electronic withdrawal options that will automatically deduct from your bank account.