As my day job is with a company that does quite a bit of business online, I must echo Rocky's advice, but simplified:
If the site doesn't prominently feature a toll-free number, or have a well-developed feedback system (like eBay and Amazon), caveat emptor.

In defense of 'drop-ship' arrangements, we do a fair amount of that and it allows us to offer niche and specialty products, expanding our value to the customer. However, we also have an elaborate and expensive inventory system that synchronizes with vendor inventories on a daily basis. It's the only way it works, and even then we trip up occasionally, usually when the humans get involved. ;-)

As much as I hope for continued growth in the kilt industry, I doubt if any kilt site (or vendor) has yet adopted this ability, so unless somebody at the other end can lay hands-on your stock product, you're risking an unhappy ending, as it were.