While that is roughly true, it's a very, very general statement to the point where I would say that avoiding function calls on principle is premature optimization. Keep in mind that the operation you're wrapping - a draw call - is expensive in the first place. Anyway, a quick profile suggests that for a small circle you can potentially gain a 7% speedup by avoiding this function call, and a 14% speedup avoiding both the function and the arithmetic:
>>> import timeit
>>> setup = """import pygame
... s = pygame.display.set_mode((100, 100))
... def myCirc(surf, color, (x, y), r, width=0):
... pygame.draw.circle(surf, color, (x/10, y/10), r/10, width/10)"""
>>> timeit.timeit("myCirc(s, (255,255,255), (500, 500), 400)", setup, number=100000)
>>> timeit.timeit("pygame.draw.circle(s, (255,255,255), (500/10, 500/10), 400/10)", setup, number=100000)
>>> timeit.timeit("pygame.draw.circle(s, (255,255,255), (50, 50), 40)", setup, number=100000)
You can decide whether that's worth it for you to avoid this function call. For me, if my game is slow enough that I have to avoid function calls to get reasonable performance, it means I'm doing something else wrong. :) If performance is the goal here, I still think it's a large amount of effort for a relatively modest gain.
For what it's worth, I would also welcome native-pygame wrappers that apply a linear transformation. But whether pygame should have them wasn't the question, as I understood it. And I can scrape by without them.