There's a new board by Trenz with a Versal chip which can do 440 GFLOPS just with the DSP58 slices (the lowest speed grade) and it costs under 1000 Euros, but you also need to buy a Vivado license currently.

Cheaper boards are definitely possible since there are smaller parts in that family, but they need to offer support for some of them in the free version of Vivado...