Couple of quid more than a standard if you find someone looking for one maybe a tenner more, but you'll be lucky, sorry its not better news, if it were a luke farmboy, you'd be on an earner.
According to eBay they are all fake so you should burn them :lol:
In all honestly, as Frank says, it is probably worth a touch more but that depends on the condition - minty Stormies sell for great prices whatever the COO
I am no coo expert, I know there are at least 2 raised bar luke FB's I have the china coo, but there is also another Meccano raided bar type that seems to command a huge premium, just checked the coo guide & seems there are actually 4 raised bar Lukes (shows how much I know), have a look here -