I had some of the same sort of questions Midatlanticdad has - what year is your son and what level of play do you think (or have been told) he'll play in college? My 2016 did not attend the ASBA showcase in Westchester last summer but I looked at the players who attended the event (if it is indeed the same one) online and some of their measurables. I will send you a PM about what I remember from last year's list.
What I find interesting about what I see online now is that they have lots of camps/showcases in the northeast. You can attend the one you listed - which has mostly northeast D1 schools listed - or you can choose one that has more D3 or D2 schools listed. I would get that specific depending on which stage of recruiting you are at. Most of the schools listed for the event you asked about attend every event in the NY metro area, are most likely paid to attend, are lower level coaches (not the HC) and are the same schools I saw rolling their eyes at one another at an event on Long Island last summer while what appeared to be freshman and sophs pitched in a bullpen in front of them. I took that to mean they weren't really that interested.
So the answer to is it worth it at all is - it depends. If your son is a 2017 and Aug will be the end to his main summer of recruiting then I would say not. I would spend the money on specific camps or even spend double the money on Headfirst on long island (which you would have to most likely book now). If your son is a 2018 and you have some time then I would say maybe - but you are already spending $695 on PG so I'm not sure what you'd get out of this additional showcase.