What's preventing the listing agent from telling false information there are other bidding just to get best offer from the buyer?
The number of offers means nothing . . . . it's the amount of the highest Offer that should matter . . . . and unless it's an Auction, you are not going to be privy to that figure.
You have the option of
"Calling their Bluff" and just hold your ground and wait and see if it closes for more than your current bid, or more than you would have paid anyway.
In this business one's reputation as a
"Liar" is almost always irreversible, and certainly not worth the risk for one dinky commission . . . . but stranger things have happened.
I wouldn't worry too much about how many other Bidders there are, or what they are offering.
Offer what it's worth to YOU. If someone else thinks it's worth more than you do, then they should be getting it. Remember, there are other houses.