Difference in price ? – simple, new technology (well newish) and a limited market.
New stuff, doesn’t matter what it is, is always more expensive when it first comes out, but soon drops
I bought a Sony digital camera 3 years back, cost £230, you can now pick up a much better version for just £70
With regards the ESC, I use Mtronics 25amp Vipers (£36) – bear in mind you can move your ESC from one boat to another, after all, you can only sail one at a time – Its also wise to buy a little bigger than you need as you don’t know yet what your next model will be !
Ken