unless someone is hardcore time traveller their store won't have rose seeds. I think they're only sold in summer, but that may vary town to town. I have roses I can sell you, but I do not have rose seeds. I can sell you a ton of orange roses, but unfortunately I don't have many red roses I'm at liberty to sell at this moment ( they're all hybrid reds I'm using to try get blue roses).
If you have any interest in orange, black, or purple roses I should be able to sell you a decent number of them. If you've any interest in any of these, let me know and I can count how many of a given colour I have then price it for you. I apologize this isn't what you asked for, so I understand if you disregard this post, I just thought I'd tell you since I'm pretty sure no ones towns will be selling roses for months