The costs of owning a serval can vary pretty widly. The cost is significantly higher than that of owning a domestic cat, but lower than some figures you may find elseware on the web quoting the cost of owning a "big cat." Owning a "big cat" such as a lion or tiger is very expensive, but small exotic cats such as servals, caracals, and bobcats are much more realistically affordable. I will try to estimate some of the costs here, but keep in mind that such things are quite variable.
First of all, you will generally pay between $1,800 and $2,200 dollars for a serval kitten. This may or may not include the cost of flying the kitten to you (something to avoid whenever possible), which runs about $200.
Your kitten may still be on formula in addition to regular food, so you might spend about $50.00 on a container of the specialized milk replacer.
You will probably spend a couple hundred dollars or more on supplies like crates, harnesses, litter boxes, leashes, toys, beds, etc.
The cost of the enclosure really depends on the materials you use and
whether you are paying someone to build or doing it yourself. You can
get a lot of extra "milage" out of a smallish enclosure by adding
platforms and tree limbs to climb on. My enclosure cost about $1,500
doing all building myself and using a lot of free materials inside it
like driftwood and tree limbs, plus another couple hundred for a
peremeter fence when I got my USDA permit. I know other people who
have easily spent $10,000. I would suggest you research the caging
requirements in your area and estimate from there.
Veterinary costs will vary according to your vet and of course what happens to your cat. In the first year you are looking at shots, worming, microchipping, spay/neuter, possibly some blood work, and routine exams. If the cat is healthy, that might run you $400.00-$1000.00 depending on your vet and if the serval is a male or female.
Every year, you are looking at booster shots (around $60 for rabies, distemper, and exam), routine blood work ($100-150), and worming ($10-50). Routine care really isn't that costly. However, if he needs surgery to remove a foreign object he's eaten (as my serval did), repair a broken bone, or treat a serious illness, you can be looking at a $1000-$5000 vet bill.
Feeding is the most substantial ongoing cost. Servals generally eat between one and three pounds of meat a day (with 1.5 pounds probably being a good average).I would say $50.00 to $200.00 a month for food and vitamins depending on meat price fluctuations.