Im looking for a genuine kilt?
Study up on your kilts. Not all kilts are the same, and I am not talking the cheap Halloween costume kilts.
In the traditional kilt lane, you have three weights. Light, Medium and Heavy. Light is for kids and dancers. Medium and Heavy for adults. It takes an experienced kilt maker about 20 hours of hard work (all hand sewn), and if that is coming from Scotland you will be paying a premium for both product and labor. Discount is around $400 for a quality kilt of this caliber. They simply do not exist below this price new.
Then you have the used market. If this is going to be your first kilt, I would not go this direction. A kilt has four seizings, and if you mess up on any of those, the kilt will look silly or sloppy. There are many budget kilts on eBay, not many used kilts to be had. You might luck across one, but again, you get what you pay for. If the seller knows what they have, it will be around $200, but then again some claim they just want to get rid of the horse blanket from an estate sell for $60. Many of these kilts are actually machine made in Pakistan. These kilts are so cheap, you might as well invest in a beach towel to wrap around you.
If you are of average size, about six feet tall, you can buy a new medium or heavy weight kilt from Stillwater Kilts around $130. These are machine made, and limited tartans, but for what you get, it would be better to go this route than sink money in a cheap crappy kilt. They assume a couple of the measurings, so you give them the absolute width and height. The shorter you are, the lower on the knee it will be. I would not buy one if you get below the knee cap. A tailored kilt would sit high on the knee. Never above, unless the kilt owner grew or likes a sloppy look. Too high above the knees
qualifies for cross dressing.
Of course, as another said, you will need to invest in implements. On a traditional kilt, you need hose (socks), and at very least a cheap sporran. A kilt pin is nice, a belt is not always necessary, especially if worn dressy. The belt would suggest informal or semi-formal. You would never wear a belt with a formal kilt. Hose can be picked up for around $10, and a cheap leather informal sporran around $40. Never white hose unless you want to be formal or silly looking. You need Ghillie Brogues for that anyways, and that is another $100-$200 for those.
Of course, there are the causal kilts such as Utilikilt (UK's) and SportKilt, where you can make you own rules with the implements. Most of the UK crowd only invest in an alternative belt and maybe some combat boots. Those kilts tend to have pockets, so the need for a sporran is not there.