You can ask opinions, but that limits input to the number of members, about 300 on Fox collector site I think. Their opinions may not include recent sales, rather just what they recalled some years back when they happened to buy one. Best to look at auctions in the not so distant past or wait for future sales to see what the market is doing in actual "sold" guns, not what they are asking. I couldn't find any to match your Fox on Gunbroker in the last 90 days, but did find this AE 20, with a cracked pistol grip, on Gunsinternational (link listed below), but would not be sure of exact selling price since it is not an auction format. I have seen sales on Gunbroker for Fox AE 20s in the selling range of $4400 to $4800, but of course condition defines that price.
http://www.gunsinternational.com/gun...n_id=100621633
Bill