They are readily available in the USA, but I do not know that they are common. I have never personally met anyone who had one nor have I personally seen one. I am not sure how much they cost, but I thought I read somewhere they are perhaps $1500? Unlike some conservation oriented individuals, I have no problem with hybrid cats such as savannah or bengal.
A friend of mine in the USA has one that costs $3000. I believe the less percentage serval, the cheaper they become so his would be in the mid range. I have no problem with them either and am interested to know more, especially regarding their interactions with domestic cats and dogs etc.
I saw one during a private tour of a sanctuary in the UK and was told at the time that there were health complications that that institution felt made the breeding of them unethical. Having just done a quick search it seems this may have been a misrepresentation.
A few years ago somebody tried to import some to the Netherlands, but they were confiscated and are now kept in an undisclosed facility.
I believe one of the main concerns is the breeding of a serval (sire) with a Bengal cat (dam) which complicates the pregnancy and birth process.
Old post but I wanted to fix a few misconceptions. I have an F7 Savannah in the UK, and her breeder keeps F1 upwards so I got to hang out with a bunch of them. Money wise it really varies, I had mine as a retired queen so cost was very little, less than one of my moggies. Kittens as pets are not unreasonable at later generations. Kittens for breeding get into the thousands easily. Health wise they have no issues but all cats should be tested for common conditions before breeding. My cat is tested for PK deficiency. As far as breeding, Bengals were involved in some early programs but that's generally frowned upon now due to confirmation and temperament issues. Almost all breedings are Savannah to Savannah of various generations or Savanah to Serval. So you can use an F1 Savannah girl (SavannahxServal) and breed directly back to a Serval for a more Serval like offspring. In this way later generations are looking more and more like Servals.