I had a spot for a Pista and passed on it. The 720s is all the performance of the Pista. If you haven't spent time in a 720s then you are for sure missing something from the 'itch' perspective. It is absolutely wonderful and is a joy to drive - hyper speed, great handling, and phenomenal brakes.
If you can buy that 1000 mile 380k msrp for 309-319k buy it. If the dealer owns it then they probably gave 290k on trade. If you expect below 300k then you need to find a 325-350k msrp car where they paid only 270k on trade. My local dealer only takes cars on consignment so in the end the decision will actually come down to the consignee.
The other thing I might suggest is buy a 720s, use it and love it, and then the new itch would be an F8 which is $100k less than a Pista and very similar performance. The Pista interior is just dated whereas the F8 has been nicely updated, similar to the 812.
2019 Porsche Cayenne S
2018 Porsche GT2RS
2018 McLaren 720S