We did a mixture - some new, some second hand. I don't think its anything to be upset about Cattyf, you shouldn't feel guilty or emotional about it. Very unpleasent and holier than thou of your collegue to say that to you.
I have 3 dc and always planned to, so some things I wanted to last all three, I bought new, and good quality and they have lasted well and I feel I made the right decision. Other things I was happy to pick up second hand if I felt they might not be used all that much or for very long etc.
Also, when I bought second hand, I paid a bit extra each time to make sure I got an immaculate one that I really liked. I really wanted a bugaboo donkey for dc 2 and 3 (small age gap) but I knew it would probably only be used for a year to 18 months so bought one on ebay. I paid £750 including all the accessories for one which was 6 months old and in immaculate condition. Probably will sell it on when I'm done for a vaguely similar amount. Its been fine as it was almost new when I bought it and only used for a short period anyway. I bought the single buggy thats done all 3 dc new and am very glad I did as its still going strong and I wont need to replace it.
I buy almost all their clothes second hand though, up to the age of about 2. When the quantity and quality tends to decline quite a bit and the balance gradually changes towards new things. I buy really good quality brands when I buy second hand, and only things that are in really good condition. Dont regret it even for a second! I can have far more cute clothes this way :o and I like nice brands which I wouldnt other wise be able to justify when they are in it for such a short period. I do buy new bits and pieces here and there too, its a cost - benefit analysis, the second hand price vs the new price etc..
Most of all what I'd say is: this is a really really special time. You want to feel happy and joyous and really enjoy it. Do what ever will help you do that. We spend lots of money on things that are "experiences" coffee out, meals, cinema etc. This is an experience too - so if you want to buy new just for the joy of it, bloody do it! I love all my baby bits and think very fondly of them now. Dont completely write off second hand though - its definitely worth researching before you buy :)