To give you an idea of the price, we bought all furniture for our one bedroom apartment from Ikea (apart from our sofa and kitchen, which was already there) and it came to 3000 euros including delivery. That's the bed, mattress, bedroom furniture, duvets, pillows, cushions, tables, chairs, desk, bookshelves, bathroom accessories and cupboards, etc, you name it we got it from Ikea!
I'm not sure what you mean by working out cheaper with the currency exchange - cheaper than what? A mate of mine spent 3000 euros on her bedroom furniture alone here in Ireland - but I'm sure people can get cheaper!
Regarding how long you should wait before you go to Ikea, I'd call the branch you'd like to go to and ask them what their waiting times are like. But it's best to order a brochure before you go there to get a good idea of what they stock, sizes, etc. This will prevent you from picking up stuff that's too large for your place. (There are instructions about ordering the Ikea catalogue somewhere in AAM - just do a search for it)
Good luck!