does anyone know the best prices on this stuff or anything else out there that is just as good or better ?

The least expensive toilet bowl cleaner will clean it beyond belief. I also I use "iron out" to get out the yellow stains.

All the best

3pointstar

Just be careful it melted my carpet on my trailer but it cleaned the hull great.

The Works toilet bowl cleaner works great.

Slimy Grimy works good too. Its a powder you mix with water. Spray on, brush and rinse.... not much elbow grease needed at all.

The Works or Sno Bowl toilet bowl cleaner. Use a pump garden sprayer to make it easy. Both are acid based so rinse very well.

On-off works great, but I use slimy grimey because it comes in a spray bottle and i can just shoot it on the hull while it's on the lift

FSR cleaner works great , can order online or pick up at west marine

Is there any danger of discoloring getting any of these on a black gel coated bottom part of hull (when using it on white deck) ?

Do a search for Ring-go on here....by far the best and easiest product I have ever used.