There are several polite ways to decline a sales offer without being rude or offensive. Here are a few examples:

1. Express appreciation: Start by expressing your gratitude for the offer and the time the salesperson took to present it. You can say something like, "Thank you for considering me for this opportunity. I appreciate the effort you put into explaining the offer."

2. Provide a reason: Offer a valid reason for declining the sales offer. Be honest, but avoid being too specific or negative. For instance, you can say, "After careful consideration, I have decided to decline this offer as it doesn't align with my current needs/goals."

3. Highlight alternatives: If applicable, suggest alternatives that might be a better fit for you or your needs. This shows that you value the salesperson's efforts and are interested in finding a solution that benefits both parties. You could say, "While this offer isn't suitable for me at the moment, I would be interested in exploring other options that may be more aligned with my requirements."

4. Express regret: Show empathy and regret for declining the offer. This helps maintain a positive relationship with the salesperson. You can say something like, "I'm sorry for any inconvenience caused, but I have to decline this offer."

5. Maintain professionalism: Regardless of your decision, always maintain a professional tone and demeanor. Avoid being dismissive or disrespectful. Remember that the salesperson is just doing their job, and it's important to treat them with respect. You can end the conversation by saying, "Thank you again for considering me. I hope we can keep in touch for any future opportunities."

It's important to note that providing a detailed answer and examples may vary depending on the specific sales offer and your relationship with the salesperson. Adapt these suggestions to fit the situation appropriately.