I think this would be very toxic for the reputation of DCS.
In F2P games, having very expensive high end content is referred to as 'whale hunting'. In games that have 'openly' followed that path, even where the 'whale' content is purely cosmetic, a lot of contempt is aimed at the developer for engaging in such practices, generally resulting in players abandoning the game and moving to others where they individually feel appreciated by the developer.
Reputation damage is real, within the flight sim and gaming community in general, DCS would immediately just get meme'd on as 'that game that costs $500 a month and that doesn't even include servers'. It'd be a punching bag for toxic pricing and poison new players from visiting the game who might otherwise have given it a go.
Also, considering the price point (and as you say, design) you'll have very few people buy in to that. Lets say 20 people dip in at that level, adding an extra $10,000 a month to the ED coffers. That's still really not big money, you could maybe hire 2 or 3 extra developers, which is great, but again isn't going to put an end to EA. However, that's not considering the loss of new users entering the funnel on account of the toxic pricing memes that'd forever be associated with the sim.