Unfortunately yes. Briefly, it used to be that the buyer's agent would accept whatever split was agreed to by the seller, so buyers would never have to pay a commission fee. Realtors used to advertise that working with a realtor was free to the buyer.
Welcome to 2017 - I noticed starting last year that realtors no longer advertise that working with buyers is free. It seems that realtors took a big hit during the recession, so now that the economy has improved and housing prices are higher, it's time for realtors to get a raise. The only way to get a raise is to increase the commission percentage or fee.
The way it works now is sellers are refusing to pay high commission fees and are fighting back. Now with technology, sellers find it much easier to sell by owner (no realtors involved), OR sign a contract with a Flat Fee broker that allows them to post their listing in their local MLS system for a small fee, OR split the commission fee with you -the buyer. In your situation, your realtor is telling you that IF any home that you buy has a low commission fee, means the seller wants to split the fee with you. Example: the seller agreed to pay 3% to their realtor + 3% to your realtor. Since your realtor wants 4% (trying to get a raise), you will owe 1%. This is negotiable and you do NOT have to pay it. Be prepared for your realtor to fight back and tell you why he / she deserves a raise. You can fight back too and tell your realtor - I refuse to pay it. Let the fireworks begin. Remember, you have the ability to walk out and find a different realtor. You also have the ability to buy a home that is For Sale By Owner - therefore you don't need a realtor. Tell this to your realtor and see whether he / she will reduce the commission fee.