Search by Ticket max price

Hi,
I’ve trying to figure out how to search for event below a certain price.

I’ve noticed that to retrieve the price, I’d have to go in EM_TICKETS_TABLE ‘ticket_price’.
How could I make such a search ? I’ve tried to adapt what was shown in the tutorial for custom search field. I’ve been able to add a max-prize new field in the search bar (header).
my field ‘pricesmax’ in the search form is well sent in $_REQUEST, but i’ve not been able to build the SQL condition.
Thanks in advance for your time and support
Simon