I ordered two extra sets of piston seals (43209-MA3-006) and dust seals (43109-MA3-006) by mistake for my '83 VF750. Partzilla's discounted price is $18.06 per set (2 each per caliper), I will send you for $10 per set postage paid. Thought they were the same as the front!, lesson learned, don't assume. These are Honda OEM, but were opened when received.
That is correct, Dust seal cost me $4.04 and Piston Seal cost me $4.99, plus $1.00 for postage = $10.03 per Piston, yours for $10.00 for 2 Pistons, just send me a PM if you want them.
Wouldn't hurt to have a new set stashed away. I just made the switch to DOT5 in the rear brakes, did the fronts back in October and so far they are great, so switched the rear over also....clutch next. I didn't remove the seals when I took everything apart, just cleaned them, so it's still the original seals in there. With the DOT5 I will probably never have any issues but I guess you never know.....