I've heard redirecting urls through httpd.conf is faster than through .htaccess. As a general rule, how much faster is it? Would I be able to access this if I were using one of the better (but not like exorbitantly expensive) web hosting services?

Roughly speaking, how many redirects would it take to have a noticeable effect in slowing down the server? How many before it has an unbearable effect in slowing it down? The pages I anticipate serving would be mostly text and php code, with few if any images.