We always had 50% up when you made your reservation. Contract allowed for percentage return of the deposit depending on time frame if you cancelled your spot. Anything less than 3 months you lost your deposit. 6 months you lost half. Deposits were held in an escrow account to insure they were available to return. Paid in full, we asked for 60 days but in reality we took a lot of 30 day payments. Amazing how many first time folks would squirrel around with the final payment, not get off the plane and want a refund.
If you had a heart attack two weeks before your trip, mom died, you died on route to Alaska, diagnosed with cancer three days before you left, you got it all back.
Read the proposed contract if the outfitter is sloppy with a contract he sure as hell going to be sloppy with something else.