Hi Abdul -
Welcome to the forum, re your pricing question there are many answers and most depend upon condition, type, supply and demand.
I have seen UN1 transmissons for sale for as little as £100 (possibly requiring refurbishment) or as high as £1000+ (possibly with Quaife ATB diff and/or other upgrades) so there really is a wide range of pricing out there.
The bell housing, if you use Renault30 and Adapter plate, is less common these days I think, although again I've seen them between £50 and £100.
Postage is always an issue, (they are not light) and also getting them adequately packaged for overseas transit is not a 'simple' option either.
Hope this has helped in some way.