RE:
Free shipping is going to be hard to come by unless you have a huge order.
My experience may be unusual, but I have had no problems with ordering online...however only from large reputable dealers.
LiveAquaria.com has free shipping for >$175 order (that is kind of big unless you are getting a pricy fish...
SaltwaterFish.com has a $75 minimum for free shipping - is very resonable..
Have ordered from both with great success.
I have done because not much choice at LFS - and who also does not give same "guarentee" (week to 10 days) the online dealers give...
Prices best at Saltwaterfish between the two - but often out of stock. - They are good about letting you know when what you want arrives if you put on your "wish list"...
Corals I want to "see" before buying...mostly as I am particular about what size, color, condition, etc...I want to go into tank...less demanding about fish (basically "young" & "healthy"

, but have not yet ordered anything really exotic...and have had no problems with up to now.
FWIW,
OmarD