I got my kits from hargle, and I highly recommend this method if you don't have much experience with PCBs, parts, ordering, etc.
As I'm learning with the N8VEM project, it's fairly easy to order the wrong parts (wrong pitch size, wrong type, etc) or to forget a part, and this is taken out of the equation by ordering the kit. And none of that is because of the N8VEM itself - it's all because now I need to order my own parts (if they offered a "parts" option for that project, I'd be tempted). That being said, though, I'm learning a lot about parts so there is that benefit! I'm glad, though, that the XTIDE was available as a kit.
Also, as hargle said, the price is great, you only get what you need, and there's another plus - the wiki instructions will match the parts exactly (which may not be if you order parts on your own that aren't an exact match) which is big for those totally new to this.
Either way, though, you can't go wrong. The XTIDE build was really smooth, and there's lots of people to help out on this site if you have questions.
Anyway, that's my 2 cents.