Does anyone know of a school offering an affordable on-line certificate in Archaeology? It doesn't matter if it is undergraduate or graduate, most important is not too expensive.
How about a Master's degree? https://www.international.unitelmasapienza.it/academics/academics-english You're supposed to travel to the university for exams but, due to covid, they're apparently doing them online right now. Total cost should be about 5000€
If you mean a real academic certificate, I think you can't beat Oxbridge. Their certificates/diplomas are reasonably priced. https://www.ice.cam.ac.uk/courses/undergraduate-certificates-and-diplomas https://www.conted.ox.ac.uk/about/undergraduate-certificate-in-archaeology