Throughout the history of football rich people have bought football clubs, made investments , club wins trophies, I don't have a problem with that.The problem is that the money involved is at multi-billionaire/state level. Our owners put in around £1.5b and in addition could influence sponsorship deals from Abu Dhabi to add a significant sum on top of that. But Liverpool, for example, have three times the revenue that had in 2008.
If a team from mid-table, even a big city one with the fans/infrastructure, wanted to compete, then they could need £4b+ invested. That's absolutely crazy - and way above even your suggestions.
Even then, Newcastle could afford whatever they want - but Everton could quite easily bankrupted themselves well before they got anywhere near the lower figures you suggested.
The only way you're going to get competition back in any meaningful way, is to reduce the revenues of the richest clubs. Either football is a sport, or it's a business, but it can't be both.
The sport has been hijacked by anti competitive businesses, rags and dippers etc to financially enrich themselves. It's wrong.