1. Start in the Middle Ground
Having flexible payment terms could give your client flexibility and breathing room while still getting you paid fill (ex: subscription plans or retainer-based pricing)
2. Offer Discounts
However, be firm and give discounts at consistent or standard amounts to avoid constant haggling or bargaining from clients.
3. Decline Their Offer
If their budget is too low, and none of the earlier options match their estimate, it's okay to politely decline their offer. But it's good if you keep in touch with them. The situation may be different in the future.
4. Include Payment Terms in the Contract
Always include your payment terms in the contract. It's critical to be clear about this with the client before you start working on the project.
Dealing with this type of situation can be tricky. What's important is you know your worth and understand the options available to you.