Return car or park in Long Term lot?
 

I am coming to NY for 2 weeks. (June 24th - July 8th) landing in JFK. On the 25th, I have a flight out to Chicago (from LGA) returning the 26th, some 36 hours later).

I have 2 price quotes for rental cars (yup, I need one, staying in Long Island).

JFK 6/24-7/8 - $470
Plus the cost of 36 hours long term parking ($40?)

JFK - LGA 6/24-6/25 - $84
LGA - JFK 6/26-7/8 $445

Which should I do? Is it better to park the car in an LGA long term parking lot ($40 cheapest i found quoted for 2 days) or to return the car and get a new one?

Any experiences with Long term parking in lga?
Any experience with Avis LGA or JFK (I'm in their Presidents Club BTW)

Thanks for the help!