Cheapest point to point wifi connection?

[Pixel5]

Im trying to get wifi to my parents garden so my dad can watch some sports livestreams while chilling in the sun.

My parents live on the 9th floor and their Balkone is heading straight into the direction of their garden, i guess the distance should be 200 meters on ground level and a little more since they would angle their antenna slightly downwards.

There is almost nothing in between the signal would maybe have to go through a tree but if everything fails we could also find a spot for the antenna where it doesnt have to.

 

id like to have a point to point connection an setup another wifi router in the garden itself, while power is no issue due to a generator in the garden it would be nice if it could stay below 20W so i can power it from a small solar panel.

 

Any suggestions for cheapest possible way to get this done?

If we could get 50mbit/s over this connection it would be awesome.

[Pixel5]

the interesting thing is the nanostations are even more expensive than the litebeams models which should be even stronger.

 

is there any good reason for that and are there cheaper solutions?