Bought mine from Natchez two or three months ago. I checked all the suppliers you listed, plus a couple more, right through to the buy button. Wasn't a lot of difference in the final, total price, BUT, Natchez was the ONLY one who had everything I wanted, in stock. Shipping on backorders can really add to the total cost, plus, it would not be good to have your new press but no shellholder for what you wanted to load.
Education teaches you the rules, experience teaches you the exceptions (Plagiarized from Claude Clay)