Top down or bottom up? Just asking...

The answer will be different for each speaker company.  Each company will have a different profit margin they determine to be acceptable for each product line/price tier.  That profit margins is first determined by what price the company believes they can sell the line at (usually determined by the target competitor price).  Secondly by the cost of materials/manufacture.  Then within these parameters, can they deliver an acceptable sound (in the opinion of the company).  When a  high end trickles down they have more pricing leverage due to brand value.  When low end moves up, they may have an advantage on cost of materials/manufacture (leveraging scale).  Though they face a headwind of any low price brand that tries to move up market using the same brand name.  Based on the experience of my past life, price leverage determines profit margin.  So trickle down is the easier business strategy.  Does that mean Wilson could make a better sounding  low priced speaker than Sony ... not necessarily.

It depends on which company makes better speakers.
Which comes down to which one makes the speakers you think sound best.
That one will always be best for you.

Why would Wilson trickle down all their tech from the $250,000 price point to $30,000?  And how, because of cost of top-tech materials and solutions.

There is no general rule and no answer to this rather nebulous question.

Some of the best loudspeakers seem to come from boutique manufacturers, for whom neither top-down nor bottom-up necessarily applies very well. Their products tend to fall in a relatively narrow price band.  Sanders comes to mind.  The company currently sells one loudspeaker, the Model 10.  Base price is $17K.  They're not chasing huge sales volumes (which may be the main reason to have a wide range of price points).

Any speaker that I can use my car buffer and turtle wax on is not for me, ho ho ho.

The speaker sound that those companies achieve can be bettered for a lot less than those out is the statosphere prices you need to keep an open mind and look to the vintage speaker market where you will find fun, musical, and emotional speakers for a lot less money.