The upsell happens after the first payment is possible, which is why it can be one click. The buyer has already said yes once. You show the next sensible thing, once, with a clear decline. Stacking five upsells onto a warm audience is how you spend the trust the first sale earned.
Use a bump for something that belongs on the same order. Use a one-click upsell for a larger next step. Fulfil whichever they accept.