If you're using it just for Photoshop, then why spend that much? You can get a good one for less than 1K. Most of today's Keyboards and mice come in USB, so, I'll suggest check out brands like Logitech, Microsoft, etc. As far as PS2 combos are concerned, I could find only one - TVS GOLD (Mechanical Feedback Keyboard) for around 1.6K.
Alternatively, you can get yourself USB to PS2 connector/converter, if you want to use your PS2 ports.