I follow the prices in Switzerland, and there I also notice a slight price increase. It is noticeable that there are very few offers of the 650S, it is with 10 offered vehicles the second rarest McLaren model, the Ulitmat Series cars excluded. Of the „limited“ 675LT there are 9 offers (only one (!!) less as from the 650S, its prices are still falling, but this at quite a high level), of the 600LT there are 13, then of the 720S are 16 offers on the web, of 12C there are 19, of the 570S/570GT/540C/ are 25 in total on offer. Sport Series prices are falling and falling and do reach slowly the 12C level. Of the GT there are 7 offers on the net, but most of them are still new cars. It seems the GT is selling extremely poorly. It can be assumed that this car will soon become unsaleable next to the Artura.
Meanwhile, the most expensive 650S models are even more expensive than the cheapest 720S. But these cars are difficult to compare with each other (poorly equipped 720S with very many kilometers vs. top 650S with very few kilometers and coupe vs. spider).
Recently someone told me that the 650S represents to him the car with which McLaren finally entered succesfully the market (together with and thanks to the all outshining P1). After the 650S the exaggerated diversification in any direction started.