What sales goals do you have if you are worried about a $600 instment?
Well, if you're just "looking into" app development, then that's a barrier. With android, you can "look into" it more or less for free. Then maybe get interested, then hey presto you have an app.
sure if you already have a business plan and money, the nputting $800 of that into kit is a drop in the ocean.
As for me, I'm never even going to bother looking at iOS app development because I don't want to burn $800 on a computer I won't enjoy using much and then have to use the wretched thing.
It doesn't stop business plans, but it does stop the causal developer. Casual developers are what serious deelopers come from.