Has anyone done strictly cupcakes for dessert? How well did that go over with guests? What might be a good estimate for how many might be needed? Of course I'll also ask the baker how many they recommend. Most online estimates I've seen suggest 1.5 per person, which I *think* seems reasonable, but I have no experience providing cupcakes for a group. I'd rather have extras than run out, but I also don't want a ton of leftovers.
It's fine - really no different than cake. In fact my crowd prefers cupcakes. There are calculators out there. When I bake for events I use 1.5 as my standard usually and rarely have more than 6 to 12 left over.
If cupcakes are your ONLY dessert offering, you may want to consider 2.0 (maybe 1.75). If you plan to have other desserts available, you could consider 1.25 or 1.0. There are a few factors that come into play (full meal vs. Cocktail or dessert reception only, other desserts being served, etc).
If cupcakes are in lieu of cake, definitely have enough for everyone to have one, even if there will be other desserts. I've seen some try to get by cheap ordering enough for 75 percent figuring not everyone will have one or prefer one of the other dessert options, but when it is taking the place of the actual wedding cake you should definitely plan on everyone. I probably wouldn't go less than 1.5 though.
We did cupcakes for our wedding. We had the option between normal sized cupcakes and large cupcakes and went with the large. We had a guest list of ~50 people and ordered 65 cupcakes, in case some people wanted extras. If we had done the normal sized cupcakes, I would've gone with 1.5 per person. We just went with chocolate and vanilla flavors so I wasn't too concerned about people taking more than one (also, they were huge cupcakes). We ended up with about 20 leftover.