What spices should I buy?

It really depends on what you like to cook.if you are a baker , you night want to
Try whole nutmegs and star anise, 5 spice powder, and cinnamon sticks if you have never used them. Buy small amounts of things that are new to you, so that you can see if you like the tastes;and so that they stay fresh

I can also recommend, in addition to the suggestions above, Ceylon cinnamon and dried ground Mexican chiles, like chile de Arbol.
Once you've spent your gift card, I highly recommend shopping for spices in ethnic grocery stores. I my neighborhood I am lucky to have Mexican, Turkish, East Asian, and south Asian groceries and I can always find good-quality spices there.

I highly recommend Aleppo pepper. I use for almost everything beyond Middle Eastern cooking. It's a really nice smoky and not too high heat.

Thank you all for these helpful comments! Yes, like bronxbaker, I was feeling overwhelmed at the options! I like the idea of za'atar and sumac. Grains of paradise and szechuan peppercorns and kaffir lime leaves. Also as for saffron- I have to confess that despite the fact that it is such a prized spice, I have never much cared for it in my cooking. Now I am wondering if a better quality saffron would change my mind! Thanks everyone for your input- you have helped me narrow it down some.

I think this is more of a personal preference and cooking habits, really. I echo the replies above - saffron, sumac, za'atar, vanilla beans, some more esoteric peppercorn varieties, dried kafir lime leaves, some good quality cocoa powder, masala blends, maybe the adobo blend.

I just took a Persian cooking class, so I would stock up on saffron and a good rose water. Orange water is useful too. I have read about grains of paradise, but haven't tried them, so I would add those to my cart. Dried lemon and lime is good, too,if you are cooking Persian foods. Remember to buy whole spices, not ground--the ground spices lose potency very quickly.

I am addicted to so many spices and herbs that I would find it overwhelming to choose. I like sweet food, so I would think about vanilla beans and Saigon cinnamon. Whole nutmeg and a tiny nutmeg grater. I like smoked Spanish paprika, both sweet and hot, for all kinds of dishes-- rice and beans, paella, chili, asopao de pollo, so I would get those, since they tend to be better and cheaper than supermarket versions. Maybe some fancy peppercorns, including Szechuan pepper, or fancy salt, including fleur de sel. Vadouvan is a weird spice mix I have always wanted to try. I first read about it in "Make the Bread, Buy the Butter". Agree with the sumac and za'ataar above. Hard boiled eggs are delicious dipped into za'ataar. Mexican oregano. Orange flower and rose flower water. This is not a very narrow list, hope it helps!!

I tend to gravitate toward Middle Eastern/North African spice blends, but I would look for a good za'atar mix, sumac as you suggested, maybe ras-el-hanout if you want to try wonderful tagines, saffron since a good-quality saffron makes all the difference, and maybe a nice roasted cumin, which could be used in all sorts of cuisines. Oh, and good cardamom pods. But get what inspires and excites you - how nice to have the opportunity to stock up, and I admire your care & thoughtfulness in making your decision!