Confession: I am cheap! Really, my husband is the cheap one but I have found that the way to my man's heart is through the amount of money I can save. This means I scour the internet(craigslist, ebay, amazon) for deals and most often buy used. Reduce and Reuse are my two favorites of the 3 R's! Baby items are used for such a short amount of time, finding a swing or activity mat in good condition is as simple as heading to your local children's consignment shop! Most baby items are made to be washed so you can just run the fabric through a hot wash and steam clean the plastic parts to sanitize and you know it is clean.
There are a few things you should buy first hand. Breast pumps are meant to be a single user item and should not be passed down. Car seats are another item on the buy new list. If a car seat has been in an accident, the seat can be damaged enough to fail but the damage may not be visible. Since you don't know if a car seat at a consignment shop has been in an accident, it is not safe to buy one. In fact, most consignment shops will not re-sell old car seats. I have even heard of fire departments destroying a car seat at the scene of an accident to prevent it from being used again.
I have also been very lucky to have a sister who has a son 10 months older than mine. Most of Kaydens wardrobe when he was little was a hand me down from his cousin, as were some of our baby stuff like the co-sleeper, changing table and swing. Now that my sister has another little boy we will be on our own for a lot of stuff but we have a great stash of clothes to get us going!
Now I have a sister in law who is due this summer and you can bet I am saving boxes of baby stuff for her to use... she better have a boy!
Another thing to consider is the storage of baby items. If you are short on space, like we are, then make use of every inch of your home for the little things like clothes and toys. Under both my kid's beds is clothing they will be able to wear or have just grown out of, sorted into boxes or bags according to size. I also have baby toys sorted by age for Liam to play with as he gets older. Big items like a crib, bassinet, swing or changing table can be harder to store. A convertible crib can be used for years but other nursery furniture can take up a lot of space. If you are not planning on having another baby right away, consider loaning it out to a friend until you are ready to use it again. Renting a separate storage space usually is not practical since you would spend more storing the item than if you bought it new.
So before you buy new, check out your local consignment shop to see if you can Re-use. And instead of throwing stuff away, pass it along to someone who can use it!