What is different than a upfront cost of $x or $x per unit versus some record keeping (which you have to do with the proprietary license anyway to pay that per unit cost) and making available source?
You're saying one cost (proprietary) is acceptable and expected, but the cost of GPL compliance is this big unexpected completely unreasonable thing.
It's the cost of compliance, if you can't comply don't use GPL code. And again, although the steps might be different this is no different than all the expense and tracking that commercial software requires. Sure you might find a company out there willing to cut you a pile of commercial source of a fixed one time fee but the contract WILL include auditing, tracking and other requirements. Maybe there is a single software vendor out there that doesn't but I'd wager that the chances of compliance with commercial being easier and less work than the GPL being near zero.
Just because companies are lazy and don't track, document and perform due diligence on their requirements for compliance with GPL does not excuse that behavior. It's incompetence on their part, even GPL software has a cost to use.