Dot matrix printers are still available but these are usually purchased for special purpose printing such as multiple part invoices where a carbon copy is created by the impact of the print head on the paper.
These machines are reliable, require little maintenance and are very cheap to run.
A ribbon costing $6.00 could last 12 months, which is a fraction of the cost of inkjet cartridges. The downside to these machines are speed, noise and print quality.
However, a modern dot matrix printer is still good value for money in some cases and may be worth a look at.
Bottom line: Choose dot matrix if you need to print on multiple part paper.