You'd pay the same tuition to go to a local school P/T though, total cost to complete is around $4k USD per year plus whatever you have to pay to a local testing center (here it was $60 per exam). Another way is just work through a rigorous introductory text like Concrete Math by Knuth and hire local math grad students to tutor you (or for them to come up with their own curriculum) but since it would be nice to spend all this time and gain actual credentials I'd be interested in distance math degrees too if anybody knows of others, University of London only has graduate level distance math degrees.