i'm still a cheapass uni student, and i've yet to spend more than $50 on a shirt, so i just check the b&s forum like three times per day for things i want.
Does it have to been online? It's really easy to find PRL shirts at discount stores like TJ Maxx. Lands' End shirts are servicable quality, but a little blousy for me.
Lands end makes a slimmer fit, as does LL bean. Those two are probably your best bets. Traditional companies that have been making this stuff for forever.
Polo rugby on sale; there should be a 25 percent off sale coming up. The fit is pretty spot on for me. I am a medium in both rugby and gitman brothers but feel that the rugby is cut slimmer and better in the waist and hips, and very similarly in the chest and shoulder.