The COP is AMD/Xilinx. I have no idea what the agilex 3 and 5 costs are, I'm not an Altera user. I will note though, having used Lattice, Microchip, and (admittedly at the start of Titanium) Efinix, none of the tools come close to Vivado/Vitis. I'm on lattice at the moment and I've lost countless hours to the tools not working or working poorly on Linux relative to Xilinx. Hobbyist me doesn't care, I'll sink the hours in. Employee me does care, though.