An entry visa can be issued directly at Lom-Tokoin Airport or at the border for a payment of 15,000 CFA.  (US$30)
It may be cheaper to get the visa on arrival than at an embassy but you may have to wait some hours at the airport for the visa.

Visas can be extended easily and for less than ten dollars. You need to drop your passport at the office and pick it up the next day.

Togo information in French - includes embassies and consulates.