the URL or domain name under Marketplace Data is not click-able for listings in BST Sites Section so if you want to check out a site than you have to manually copy/paste its address in browser since the new listing method most of the sellers don't put the link in the post body and just enter it in Marketplace Data. so it would be very helpful if you can just make it a link you can do a no-follow if you want
The link wouldn't always be valid... since it's just the root of the domain, and not www.domain.com for example.
you can make it with http://www It is just a bit annoying if you have to copy and paste the urls, anyone interested in buying a site is definitely going to check it out 1st