Surely if the business is named 'disruptive' then it stands to reason that there are businesses working in the current market. e.g. Uber was disruptive to the Taxi industry.. so you can easily calculate the current prices based upon pre-disrupt.
Alternatively, you can simply put numbers to that which you intend to sell.. e.g there are no other apple sellers, therefore I will price my apples at £5 per apple; if people don't buy your apples because they're too high priced then simply lower it.
Most people don't know what you priced it at 1 month / 1 year ago.
You can also price using the ABC Actual base cost and then simply add 20% - ABC takes into account all the direct and indirect business costs then divides the number by the predicted sales + 20%.
Viability of a product, for example you make snow shoes, put them in a market and they sell, but the business won't scale past those snow covered countries and seasons.
I, usually just stick down 4 numbers on paper, zero, low, medium, high and stock prices... I then project, if I sold this number then I'd earn this much at this price, but the expenses cost this much so I'd end up owing money, therefore price is too low.
You could though, think of it this way...
I make a pair of slippers they are worth £1 because that's what it cost to make. I then put a logo onto it CK and now the slippers are worth £200. If the slippers don't sell within 4 months then I put the Sale price on at £100, half the original cost. I therefore either make £199 or £99 but either way, the brand and not the slipper made me a ton of money. So, it doesn't really matter how you price something, just matters how long you can wait for a sale.