It is a sliding scale you're right there and like many sliding scales either extreme is ridiculous irl. But yeah that's the very basic criteria for a free market. With regards to the minimum market value thing...I'm going to go off on a tangent but it's relevant...Sorta.
To set up a business you need land, labour, capital, entrepreneurship. Each of these will have a different cost to start with and a sort of upkeep cost. Land is the physical location of your business, an easy one to work out: either buy land or rent it (even bought land has upkeep because you take maintenance into account). Labour again is easy enough (initial cost of labour is things like paying construction workers to build an office, upkeep is paying your staff). Capital is anything which can be assigned a monetary value, so it could be literally money or it could be that you need some kind of machinery to get your business to work or a pc or whatever, generally things. The initial of this is easy to work out (exactly what you've spent to get the business running) but the upkeep usually happens on a sort of 'as it needs fixing' basis so you put in an estimate. The entrepreneurship you provide yourself; it sort of represents the opportunity cost of your person being used for this project and not something else but also is a measure of profit. That part honestly always eluded me and I didn't see why not just call it profit...
Anyway: For entering into a large market with either monopoly or oligopoly (by the by, a monopoly is defined as a business with 25% market share) you'll need to be competitive in price which is difficult because they'll have benefits from economy of scale and brand loyalty and such things, especially if the business has been around for a long time. So, you have all your initial expenses and you have the yearly/monthly/daily/hourly 'upkeep' costs. The upkeep should change according to the market (e.g one year rent may go up due to housing prices) but the initial costs will stay the same (with regards to paying them). The businesses already in the market will have paid their initial costs already and so will just be paying the upkeep which is where they get their predicted yearly expenses from and then decide whether its still profitable to run the business. For the one starting up they ordinarily would have to factor in paying this initial start up cost but because they can't afford to do that due to needing to have a competitive price (just talking about necessities btw, otherwise things are different) they are forced to operate at a loss for a while until they have paid off the initial cost. Although by that time they can be in debt a lot of money which then locks them in the market or else they go bankrupt.
So the moral of the tangent is: you either get things that are affordable or you can have more choice. Although having said that, perfect competition also drives prices down while giving maximum choice. But it's a unicorn.
Happy to explain economics, finally there is a topic which I have at least some credentials in xD