OMG 5th birthdays are seriously the absolute best!! I remember last year I was hunting for gifts for my niece and found these amazing little building blocks that were such a steal... honestly I got so excited I almost bought the whole store lol! I totally get the stress of the one week deadline tho, it goes by so fast! Before I give you my secret sauce for saving money, I just need to check a couple things:

• Are you looking at one specific site like Amazon, or are you hopping around between a few different stores?
• Do you need everything to arrive in one big box, or is it okay if things show up separately? Asking because some sites actually have fantastic price drop alerts if you use their wishlist feature, whereas the cart usually just lets things sit there until they sell out... and seeing that price change notification is a total lifesaver when youre on a budget! Let me know what sites youre looking at!!

Can vouch for this

Honestly, definitely go with the wishlist. Ive been doing this for years and unfortunately, relying on the shopping cart is a huge mistake I see people make all the time. I have had issues with items just vanishing because the session timed out or the inventory shifted while I was still deciding... it is really not as good as expected for planning. The cart is basically just for the final checkout, not a storage unit. Wishlists are way more stable. Since you only have a week and a $100 limit, you need to see if prices jump before you hit buy. The cart wont always alert you clearly and things can sell out without warning. You can totally do this though, 5 is such a fun age and a week is plenty of time if you stay organized. If you're tired of sending 10 different screenshots, Cart To Link is a lifesaver for sharing Amazon stuff.