Race selection does not impact the cost to upgrade any skill -- at all. In any way.
All of the starting PCs have way too many wasted points, making Custom the best option. This is long established, but you can look for yourself. For example, the Shaman has 89, which looks tempting compared to Custom's 75, but 3 are in Melee and 1 in Pole for a total of 17 points that are probably wasted -- and that's assuming you want a character who will cast both types of spells. Similarly, the Soldier at 87 wastes at least 13 points by training in both Melee and Pole, which is redundant, plus 3 for that useless point in Defense.
Also not considered is the effect of trainers. In A4, there are a few trainers available fairly early on, so points in, e.g., Spellcraft are also kind of a waste. I think that applies to Arcane Lore and maybe Nature Lore as well, but I forget the A4 list exactly.