1st pressed vinyl best ones to get ?

Opinions please on this one . I have been searching ebay for early copies of pink Floyd and Led zeppelin  and am amazed at the price of some of these. However  I managed to obtain a Ist pressed issue of Led Zepplein 2 for £45 in very good + condition ( still not arrived ) .
some people on these site say the 1st pressing is as close to the red tape copy you can get so should be the best sound. Would love to hear your thoughts, as I'm sure there are many of you that have 1st pressings or have heard them. I also checked on discogs of a similar condition vinyl and was going for well over £300. Did I just get a bargain , or am I missing something ? 
Your knowledge and help would be great and thanks in advance . Oh I checked the matrix numbers and they were the same .

Steve