You can ask the seller but s/he is not required to respond or disclose (and some might even block you for asking).
My advice is to simply think of it as the seller's bid to buy his/her item back--you don't know what anyone else is going to bid, and you don't need to know. Just bid your TRUE maximum at the time of your choosing.
Bidding very late has several advantages, but if you feel you need to know if your TRUE maximum can meet the Reserve, you can bid it early and then you know if your bid can meet the Reserve. If it does the price immediately "jumps up" to the Reserve Price without requiring any other bids to drive it there. If it doesn't cause the "Reserve not met" to go away then it is lower than the Reserve and you can move on without fear of the actions of others making you the winner and obligated to pay at the end like when you are simply outbid: if the seller lowers the Reserve Price eBay will automatically lower your hidden maximum bid if needed to keep you from meeting it retroactively.
