Not sure at what rate you're leasing a Tesla A. But isn't it cheaper to buy, for example, a 3060?
Ofc I'm not familiar with shipping and stocking in your country

I'm overseas ATM so I'm in the process of leasing a custom server from walkerservers.com. They're the only guys who accept crypto and offer GPUs at the same time.
They also only have Teslas, so no GeForce or Quadro for me.

(you gotta request a quote from their sales dept for one, they aren't available in the product listings.)
PPS.
do not get a 3060 until someone confirms whether they throttle on these programs, that card in particular throttles itself for ethereum mining, and I have no idea if it classifies private key bruteforcing as ethereum mining, as they both use ECC, and'll throttle on these programs too.
I see, I could free up a windows desktop with a 3080 or 3070 if thats something you're willing to work with?
Would need to request and need a time-window (1 week, 2 weeks?) for it, but could work it out for free.