I'm ordering through the chain of independent record stores that has a brick and mortar outlet here in my hometown (Plato, in Utrecht, Netherlands). Best of both worlds: they allow me to preorder and will have it ready for me at the day of release. PLUS I support an indie store. They want €27 for it, which seems fair (e.g. Rarewaves would set me back €23 here in Holland).
There really is no need to apoligize for not paying silly money for just a slipcase. I like SDE for what it is, but the way they operate sometimes grates. For example last time when they announced SDE #36 and you could buy a bundle with the (as of that moment still unannounced) #37 at a discount. The moment #37 was announced, this bundle (and the discount) was suddenly not available anymore for "reasons to tedious to go into". And there are more examples that made me wonder whether we're dealing with a 'cottage industry' that sometimes has it's flaws or whether they are just being canny. One thing I do know, is that they are persistent in organising their shop exactly as they want to (which is obviously their prerogative) and it's their choice to put things on offer that, admittedly, are of very little interest to the vast majority of buyers (such as an 'exclusive' slipcase). And to their benefit: they do not seem to try and make an appeal to us in which they plead for our business because otherwise they will not endure blabla. Their attitude always seems to be: no one is bending your arm to buy anything.
I will buy from SDE when they put something on offer that I like and that warrants the (also for mainland Europe) quite expensive p&p.