The "surround" is the circular piece of foam that connects the cone to the metal frame. The photograph is a prime example of foam rot typical for speakers of that era and the 80's.
In that condition they are not worth very much. Depends on what condition the tweeters and grills are in. Vintage speakers (or any for that matter) or worth the most in original condition. People that know these speakers will also know that they are susceptible to foam rot, so having the surrounds replaced is not uncommon. The value can also depend on who did the repair. Some buyers will want the work done by a professional as opposed to the novice owner installing a kit.
I agree with the comment on the grills. As these speakers are collectable, if the drivers or cabinets are shot, there is value in a set of grills in good condition.