I'd remove the oil filter and check to see if that is where the oil was leaking from. pretty common problem if the filter isn't changed regular or you use automotive filters and the ski is run in slat water. or throw a quart of oil in it, wipe the filter off with a clean rag, wrap a new one around the filter and start the engine ( idle speed only) after ten seconds stop the engine and examine the rag, if it's full of oil, the dealer is trying to scam you.
we'd expect you to identify the crook in exchange for this advice.
yammie engines are pretty tough. they can often withstand a low oil event or two before major damage happens.
if the rag is oily replace the filter, pop three quarts of oil into the fill tank and fire her up. no engine warning?...problem SOLVED
of course if the exhaust is smoking like a mosquito fogger, you likely have a broken piston ring, but that's another story.
I'm sure you can find an independent shop in your area who will quote the repairs for less then an hour shop time. ( $75-$125)