Most releases (homebrew: typically no license or IP agreement made in limited batches, independent: typically with legal agreements/licensing and larger production runs) are approx $75 USD.
Intellivision games require a relatively rare plastic shape housing, custom chips, and unique production process. Producers tend to replicate the Intellivison comercial treatment of the early 1980s when it was a boutique system, so quality boxes and overlays and printed manuals are also included, which drives up the price.
ROMs tend to be in the $15 USD range, sometimes depending on LTO Flash ID locking.