Asking a seller to undervalue their product on the invoice exposes them to a potential loss in the event of shipping damage as shipping companies generally will not payoff more than the items declared value. If an individual wants to scam their government that's their business. given some of the tax laws I can even understand why they would. But asking me to be complicit is a step too far.
BTW, I am not opposed to international sales or purchases, though my preference is for US transactions, especially for larger purchases. These are always paid for with USPS Money Orders and the funds delivered via the USPS. If there is a scam or deceit it's a Federal offense and the likelihood of the authorities taking action is greater. I may not get my money back, but there is a greater chance the culprit would not do it again! (yes, mildly delusional, but it brings me comfort...)
BTW, I am not opposed to international sales or purchases, though my preference is for US transactions, especially for larger purchases. These are always paid for with USPS Money Orders and the funds delivered via the USPS. If there is a scam or deceit it's a Federal offense and the likelihood of the authorities taking action is greater. I may not get my money back, but there is a greater chance the culprit would not do it again! (yes, mildly delusional, but it brings me comfort...)