Lange Platinum 1815 MP (limited to 150 pieces), you will see that even Lange limited edition can soar really high.
And if you look at the Journe Black Dial Boutique edition, not limited , though selling strictly at full list (in which you can buy the regular version with a good discount),
simply fly off the shelves at lightning speed.
Personally, I feel that as long the limited editions are beautiful and from respectable brand, they will comand a premium price.
And at what price, it really depends on the scarcity and demand. Just look at what the PLM is commanding now 
There are 500 Lange Anniversary out there while there are only 300 Patek, not forgetting it is a rare stainless steel.
This make the Patek 5565 very desirable for collectors.
There will be many who think it is not worth it but there are also a few who will not mind forking out the premium to include it in their collection.
It only takes one people to think it is worth it to close the deal.
I for example is one 'fool' who thinks it is worth it to go for the Pisa Dato since I really love Datograph but can't stand the Black Dial.
I pay huge premium on it and do I regret it? NO. There's only 10 pieces in the world and I'm proud to include it in my small collection 
There are many out there who pays premium on their limited edition Journe, AP, Patek, VC.......but as long they feel happy about it, cool.
If I have to choose over the Lange Anniversary and Patek 5565, I will choose the 5565 purely becos of the aesthetic. But I really do love the Lange Anniversary too.
The stainless steel appeal on 5565 is irresistable.
Just look at PP5980 and PP5960. The stainless steel 5980 is commanding a price very close to the platinum 5960 which also has an annual calendar.
I also remember that the SS Lange1 command a price in auction around the MSRP price of a platinum model, which is not that far from the patek 5565.
So I personally think it really depends on the model.
If you show me a Stainless Steel L1 and this Patek 5565, I will gladly choose the L1 ;-)
Lovesss*CL