If it's a Night card it doesn't need to let you play treasures. It's definitely stronger because it's non-terminal though.
I wouldn't say that it's definitely stronger. Actually I think it might be weaker. With the normal Black Market, you get to see what cards it gives you and then if you don't want any of those, you can buy something from the kingdom. With Night BM, you have to make that decision without knowing what cards you would get, which is a pretty huge deal. Also, you can't buy something from the Black Market and then immediately draw and play it the same turn (which happens a lot in regular BM games), and you can't do the usual BM tricks with Tactician, Menagerie, etc or any other Action card interactions (doesn't happen very often in regular BM games but still happens sometimes).
EDIT: Also, you can't use the dollars for buying something from the kingdom, which is another big deal.