You can make your own low-cost SuperH as SuperH patents (but not brand name) have expired. If you are interested write to the j-core mailing list with what kind of chips (is it more micro controller or older mobile class chip) you are interested in and see if they have a chip already that suites that need. If the people behind J-Core ever print silicon they surely won't mind printing and packaging in larger numbers and sell some as part of the batch.