…Okay — I'm back. I'm afraid that explains nothing. The website is really just a host, & there is very little info either about or provided by the shops using the site. So these are just very likely to be DRM protected MP3s, & there's nothing you can do about that except email the Seller & ask them… er… well,
why.
There is a question of "fit for use" here.
From your point of view, to move on there are two ways to go. You could email me one file (just one, please!), but all that will happen is I will say, "Yep! They're DRM!". The other way is to use an utility such as WireTap Pro to record the audio when you play the files in iTunes. Then of course you can import the WireTap audio into Logic. But even though WireTap Pro is pretty cheap (good, though), it means additional expense for you.