Cheap transportation to/from NYC for OOT guests?

Cheap transportation to/from NYC for OOT guests?

FH's family lives in Europe. They will be approximately 10 adults. All hotels in NYC are too expensive so they will most likely be staying at the wedding/reception site, which is a hotel in NJ that's 8 miles from Manhattan.

His parents are old and he doesn't think they would be able to figure out the bus system at port authority so would like to organize a car service to pick them up from NJ and bring them to NYC, and also bring them back 4-6 hours later.

Any companies that do this for cheap? The cheapest rate I got was from Carmel and it was $150 EACH way!