Since you're a bigger guy, you can also go with Joseph A. Banks. The tailored/slim fit shirts are only slim in comparison to JAB's regular cuts and should be fine on you. Their numerous sales should allow you to get three shirts for $90 or something similar. I've always thought the quality of the JAB shirts is pretty good for $30 a shirt, if they fit.
You can also try Brooks Brothers during the upcoming Friends and Family sale. You should be able to get three shirts for $155 and many times the SA's will let you add on a 4th or 5th shirt at the same discount pricing.