can I use Amazon even if more expensive than seller website

Trademark issues are becoming more and more prevalent these days. If you use that website as the "submission" website for an Amazon affiliate account, you may be denied an account there as well.

If you have an Amazon account already, then you may be able to do that without getting reviewed by them. However, I'd stay away from promoting that domain on PPC, as their guidelines are also getting strict about trademark name bidding (your URL will be in your ad and it has the trademarked name).

Does the vendor have an affiliate program themselves that you could join? If they know that your whole purpose is to SELL their product and you will be featuring it in a positive way, they may be okay with that, because that's money in their pocket. But they also might be touchy about their trademark anyway.

Many companies are getting touchy these days, and are forcing people to hand over the domains to avoid legal hassles with them. Hopefully that won't be an issue for you. But I'd be careful how much time and money you put into the domain just in case you end up losing it.

Yes, I'm being negative here. I just keep hearing these stupid horror stories, and I've had 3 of my Commission Junction sellers come back to me in 2 months with revised affiliate terms that we have to follow where you are not allowed to promote their products using a variety of trademarked terms.

Better to be forewarned of a potential problem in my book.