I've also thought that these pumps were pretty expensive.  Look at the materials involved, and you will find the difference.  The use of plastics in RV faucets would not seem to bring any hazard, but the question would be the internal parts.  Why not question the manufacturers for their opinion.

If it were only a failure of pumping ability, I'd consider it no big risk.  However, you would want to be sure that internal corrosion would not bring on a health risk.

Steve

What I found out is that the biggest differences between the manual galley pumps marketed for RVs and those for the marine market are the diameter of the hose fittings and the flow rates. The RV pumps discharge about 1 gal per 100-120 strokes, the marine ones 1 gal per 50-60 stokes. The marine ones all are sized for 1/2 to 5/8 hose or reinforced tubing. The RV ones for 3/8 plastic tubing. The marine tanks, too, are fitted for 1/2-5/8 hose or tubing. The marine ones can all handle raw water, but none of the RV ones are recommended for raw water.

The hose diameter and pumping rate is an issue if the runs involve turns and distance. The reinforced PVC tube can bend into tighter turns without kinking or collapsing. It isn't available in 3/8, so with the RV pumps I'd have to settle for unreinforced tube.

I am going to spend the money for the marine pumps. Whale looks like the best value.