So, out of curiosity... I did a little math on the potions sold for healing purposes (Red, Orange, Yellow, White) to figure out which one was best... I will now share my findings!
Red potions are the best HEALING for your money, as they give a little over 1 health for each zeny that you spend on them.
White potions are the best healing for your WEIGHT LIMIT, as they give a little over 24 health per point of weight they're taking up in your inventory.
---- Math ----
Red 50z, lb 7, hp 45-65 (55 avg)
~7.86 hp/lb, 1.1 hp/z
Orange 200z, lb 10, hp 105-145 (125 avg)
12.5 hp/lb, ~.63 hp/z
Yellow 550z, lb 13, hp 175-235 (205 avg)
~15.77 hp/lb, ~.37 hp/z
White 1,200z, lb 15, hp 325-405 (365 avg)
~24.33 hp/lb, .~30 hp/z
As you can see... the prices really shaft players, just in general. XD