Cats are cats. We have two cats, and the two dogs. Very different critters.
Cats are DEFINITELY less work. Although its not in the "good cat owner" manual, we can and have left them alone for the weekend on many occasions (multiple big bowls of water, dry food (which is all mine eat) and clean litter boxes) and they are just fine. For longer trips, someone just needs to check in once a day, or once every two days . . .
Although cat lovers will kill me for this, cats are just NOT as smart as dogs (or at least, not as smart as smart dogs). Its not a trainability thing . . . the cats just have nowhere near the problem solving capability of the dogs. They are, however, quite good at training you . . . because following you around the house incessantly mewing is a great way to get you to do something.
It depends on the cat, but by and large, they aren't going to bond with you in the same way as a dog. It doesn't mean they don't love you, but its not the same sort of bond at all. Firdaus, my 18 in November cat, is bonded to me, and clearly prefers me to all other humans and obviously enjoys just spending time with me and being petted or even being nearby. I was told that while I was in India she would go to the door every day at the time I used to come home, looking for me. I love her with with all my heart. But its a very different relationship than with either of the dogs, who follow me around quite actively (Firdaus will sometimes follow me . . . sometimes) and look mournful when I leave them (she just goes to sleep). The dogs want/need to be with us. They want to do things for us (or at least are happy to do so). They want to play with us and interact. The cats, even Firdaus, want to be with us when they want to be with us.
No idea if they are cheaper. The supplies are, I guess, but I feed superpremium to the cats too. But I've spent a lot of money on vet bills and such over the years . . . and I was pretty much broke until I started working at the firm, so the dogs came right when I had some money to spend, and thus they got a lot spent on them. I'd say cats are somewhat cheaper, but they do get sick, and because they hide it, they may be VERY sick by the time you get them to the vet . . . and that's a big bill.
But don't get a cat if you want another dog. Get a cat because you want a cat. There are dog-like cats (and cat-like dogs) but most cats, are well, cats.
Notably, all my cats have been rescues and I've never seen a need for a purebred cat.