No offence to anyone but honestly I wouldn't - Now I don't know "Shaz" as some of you might do but inorder to do a 3000 dollars SE, I would really have to trust my guts on the guy and his service. You're making a thread asking for how "secure this is" and honestly if nobody has done a 3000 dollars SE from microsoft from the same guy, then I doubt you can use them as advisor. It's like saying because a guy can SE amazon for 500 dollars 100 times, means he could SE apple for 5000 dollars one time - it doesn't work that way (sadly).
I've heard on other forums that amazon often bills people for kindle (this is a 50-100 dollar product), why wouldn't they bill for a 3000 dollars item, especially when they bill for surfaces? (ofc Shaz may have an method that I don't know)
I'm not saying you not to do it - but to include the risk that you may have to pay full-price for this item which may happen for everyone, even people who SE amazon, if there wasn't a risk then why wouldn't he just SE him and his friends lots of these products and make bank? because there ALWAYS is a RISK.
Conclusion: now if you have a drop, could use a VCC preloaded with 'x' money to avoid a 3000 dollars lose if they do happen to bill after 'x' time then go for it. If you can't afford the risk of being billed 3000 dollars then don't.
Btw my post wasn't meant to offend or saletrash anyone nor do I know or claim to know Shaz method or his ability to SE. Simple giving my opinion to a scenario, what may or may not happen.