It's not uncommon for a member to ask for 100% of the money up front. There are many who have different payment terms. Terms do vary and are entirely negotiable.
For example, I know some members ask for partial payment when the confirmation letter is received and the rest 60 or 90 days ahead of arrival. A lot depends on when the owner's points expire - if an owner would have little or no time to re-rent if the renter cancels, he/she will generally want more money sooner. Most owners consider rental transactions non-refundable.
It's all negotiable. If one owner's terms make you uncomfortable, you can always look for someone with different terms. My advice is to be absolutely sure you understand and are OK with the payment schedule as well as with the cancellation terms.
Best wishes -