1) Hand Me Downs
This is not the time to stick your nose up in the air and say that baby will have all the best brand spanking new items from the poshest of brands. If you have a friend or relative offering you stuff, TAKE IT! Babies and kids grow out of stuff so fast, you'd be amazed what great shape clothing is in even after being handed down a few times! Same goes for toys, furniture, etc. You'll want to make sure the item hasn't been recalled or isn't in compliance with new safety regulations, and you should probably cough up the dough for a new baby mattress, and car seat (if it's older than 7 years or if it's been in any accidents, do NOT take a used one!), but other than that all other items seem fair game!
If you don't know about Craigslist, you have been living under a rock. It's amazing the deals you can find!! Be careful about fraud, be wary about going to someone's house alone especially if you haven't spoken on the phone, and be careful to inspect for bedbugs!! Other than that, go nuts!! We got an awesome Babyletto Mercer crib delivered to our door for $75 (new is well over $300). This is also a great place to sell (or give away) your own stuff!
See number 2 about the living under a rock thing. Ebay can be great if you like the whole auction thing. You can get some great deals on new or used items, and sell them when you're done with them! Hoorah!
4) Online Shopping
Amazon and Diapers.com both have great prices and offer discounts with diaper subscription services (like 5% or so off if you place an on-going order), and free shipping over a certain amount.
4) Discount Stores
Marshall's, TJMaxx, Century 21, Burlington Coat Factory, Target, Walmart... to name a few!!
Talk to friends and find local swaps. Usually their is an entry fee to the event and you bring items you no longer need and go "shopping" around the swap and pick up items you want. If your area doesn't have a swap, maybe you can organize one!
Finally, when you're thinking about your budget and how will you ever buy XYZ to keep your baby happy, why don't you take a moment to think about how little babies actually NEED. Sure the exersaucer with all the bells and whistles looks super fun, but perhaps your wallet or your micro-home won't allow it. Don't feel bad, not having every toy under the sun will not make you a bad parent and will not negatively effect your little one! They need loving attention, they need nutrition, and they need a safe place to nod off. If you haven't seen the documentary Babies, it's a great one, showcasing families raising their baby through the first year in Japan, America, Mongolia, and Africa.