I'm waiting for some paint to finish drying, so I figured I could get you a list real quick. Everything on this list is based off of WGCShop, without shipping. Also, not all of the products were currently in stock, so you may have to look around.
FF-PSS2-TC First Factory - Teflon Cylinder for APS2 US$102.00 US$102
GD-APS2-03 Guarder Ultra Light Aluminum Piston for APS2 Series US$29.00 US$29
GD-PT-APS201 Guarder Taper Cylinder Head for APS-2 Series US$20.00 US$20
FF-PSS2-SG First Factory - PSS2 Spring Guide for APS2 US$30.00 US$30
FF-SP-150SP First Factory - PSS2 150 Spring for APS2 US$21.00 US$21
FF-PSS2-PH First Factory - PSS2 Piston Head for APS2 US$12.50 US$12.5
GD-PT-APS208 Guarder Steel Bolt Handle for APS-2 OR & SV US$36.00 US$36
Grand Total Cost: US$250.5