How long is it taking to receive a preamp?

These guys have some in stock, buy one, no waiting. Some are less than $10-20K

https://upscaleaudio.com/collections/preamplifiers

Demand is high and parts are scarce.  It always depends on the brand and how lucky/unlucky you are but know transformers and semiconductors have been miserable to source.  

So how is payment being handled for delays?

my dealer dont accept cc.  Wants a wire of 50%. Paying $10k cash and uncertain delay.

Any body buying a preamp? High end hifi sales really bad?

Actually the industry is doing well from everyone I've talked to. But one thing that has made things tricky is supply side shortages. Shipping, especially from overseas, is delayed as shipyards and the like are short on employees as are the airlines.

Depends on the dealer and the product. 

For me it is driven by what I have to pay, when I have to pay it and what flexibility I have to cancel.  If it is a product where I pay nothing till it ships, I can cancel anytime prior to production, or is an item that sells quickly, I will take a modest deposit.  If I have to put down a 50% deposit, you put down a 50% deposit.  

If I have to pay for the entire item up front at time of ordering (yes, some companies require this), it is a special order item that I can't cancel, etc... then you will pay a significant deposit or for the whole thing at time of order and terms will be clear if the deposit is refundable which again, is driven by my terms.  

If you cancel and am out $10K or will be bringing in an item that might take me a really long time (years) to sell...that is where sometimes terms are not appealing.