I feel like the way to deal with this situation is to ask them to pay a $1000-2000 deposit to take a day to interview, refundable in the event that the company

I feel like the way to deal with this situation is to ask them to pay a $1000-2000 deposit to take a day to interview, refundable in the event that the company makes an offer meeting certain conditions (e.g cash salary >= $amount) Most companies will say 'no', the tiny minority that say 'yes' are the ones that are serious. Clearly only works if you have enough 'dealflow' to end up with nonzero takers