The traditionally shaped coffee or tea cup often has a wide mouth and a narrow base which could make it significantly easier to spill from. A true saucer designed to go with a cup, as opposed to just a small plate, is characterized by an indentation in the center which helps to hold the cup in place
Frankly, I’ve been checking thrift stores for more dishes and suchlike items, rather than shopping at retail or discount retail outlets. My thinking is that 1) I’m gonna save lots of money 2) if the dishes were gonna break, they would have broken already and 3) the stuff available at thrift shops seems to be consistently more attractive than at the retail outlets. There’s still ugly stuff at the thrift shops, but it seems that the proportion of ugly stuff is much smaller.
You might be amused to know that I know a local restaurant owner who shops at the local thrift shop for her restaurant supplies.
For that matter if you know a restaurant supply store that sells to the general public, you should be able to find all the cups and saucers you want. Restaurants seem to be the largest market for this.
I had originally said:
to which Pithy responded:
Oops, that “mugs” in my parenthetical remark should have been “cups.” I thought I had cups and saucers with my set, but it turns out I have oddly shaped mugs (which are on the top shelf of the cupboard, whence they emerge only for dinner parties – thus my not knowing if I had mugs or cups) and small plates without the indentation. I rarely use those plates, which are too small for a sandwich – a year or so after buying the set, I went ahead and bought the salad/sandwich size plates, which are what I use 95% of the time. (I live alone and rarely eat the type of multi-food meal that needs a full-sized plate.)
When I said “purchase … as an extra,” I meant the cups and the saucers together, but since that would seem to be what the OP wants, I’m not sure that would be a problem. Not sure if china or stoneware patterns that let you buy a la carte would sell saucers only or not, it would probably depend on the maker/pattern.
Awww, c’mon. You’re a saucerer. So let me see ya saucer? Huh? 
Moving thread from IMHO to Cafe Society.
Do other people have a significant problem with rotten eggs? I cook a lot, and I’ve never, never, ever in my life found a bad egg. I mean, I check them to make sure they’re not cracked before I open them - is it such a problem that people make their scrambled eggs in such a way as to have at least four dirty dishes (saucer, bowl, pan, and plate)?
I wondered about this, too. After all, they keep practically forever under refrigeration.
I do use a bowl–not a saucer–for fried eggs. This is only in case I accidentally break the yolks, in which case I can use those for my wife’s scrambled eggs.
Isn’t the saucer where you put your cookie? Or was I brought up all wrong?
FTR here’s one of the ones we bought recently.
It’s interesting that people talk about saucers as something they’ve never seen and don’t understand. While it’s true they represent a bygone era, as far as everyday household accouterments are concerned, the type pictured here is typical of what you might see in any white-tablecloth, full-service sit-down restaurant. Most people have probably seen these in places like that, but it’s human nature that we generally don’t pay attention to the crockery when eating in restaurants.
I actually have a set of cups with accompanying oblong plates, which is perfect for a cup of coffee and a slice of pie. The ridge/indentation is at one end of the oblong. This set of cups and plates belonged to my grandma.
I’ve found it easier to keep an egg yolk intact when breaking into a saucer rather than a cup or a bowl. Also, if making poached eggs it is really easy to slide them into the pan of water.
Regarding bad eggs, it is rare that I found one- and when I do, it is usually in free range or farm eggs. I am pretty particular though- if an egg has blood in it I won’t use it although I wouldn’t say it was bad.
Around our house, saucers are mainly used for feeding the cat. I don’t think anyone’s ever used it for sticking under a cup.
Doesn’t the cat tend to push the food onto the floor with this arrangement?