hey, no probs,
you wont get many creatures on the rock, to be honest, i would advise going for "cured" rock, which is what i suspect you have been quoted at that price,
this is kept in large tanks usualy and kinda rinsed for about a month, taking all the dieback, off the rock, along with nasties such as bristle worms, mantis shrimp etc, so when you get the rock it looks pretty bare.
there may be small stubs of algae, which dont take too long to re-develope, but, you are looking for rock which has a good covering of coraline(purple, green, white, yellow) algae, which is hard to the touch, with a slight smell of seaweed (not too strong tho)
you wont get alot of corals, (which i thought at first, you did
),
you may get a couple of polips or something but dont expect too much, then you wont be disapointed as i was at first.
the second option is "un-cured" rock, this is the same rock, just not rinsed (i cant think of a better word, but you get what i mean)
this will have alot more on it alive, but also alot more dead stuff, and will absolutely stink
it also means you need to cure it youself which is alot of work with water changes etc, and alot more time before you can stock the tank.
the quality of my new rock was ok, just a bit lacking in coraline alge, but its starting to come back now, after a week, so not too bad, i had asked then for odd shapes for decor, so they had to go for that first, rather than colour i suppose
i got my 2nd box from fantasea too, which had more coraline on it, thats all.
here is a link you might find usefull for all aspects of reef keeping, lots of info
http/www.reefs.org/
the key thing you get from live rock is the bacteria living in it, this acts as a filter and is the most usefull park of having live rock,
this is why i have three and a bit boxes in my tank and will be adding more at xmas, i use a skimmer and my rock and that is all i have for water purification.
stay fluffy
ty