What do you mean by bulk? I ordered 8 sheets today and I think the price was around £37 + VAT. That will be latvian (better than russian) but may well have some patches where knots in the face veneer have been removed.
Wow, prices of this have crept up loads since I last looked (few years now). Shame we havent got any 28mm sheets left at work (russian birch with the odd 'dutchman' (a Normism??) in the face), I'd ebay them £££££
I pay about £35/£40 for 18mm lat ply from Meyer timber, probably the same place as Dodge? Its OK for carcasing, but has some patches and the odd bit of colour, so I don't use it for face work. But you can get the good stuff, perhaps you have been quoted for that? But it seems cheap for that, so I think you should ring round a few suppliers as you have been quoted high IMHO.
Totton Timber want £62.83 delivered and I expect that will include your area.
They are generally high price but good quality.
They quote Latvian/European so I don't know if you have any choice as to which.