Actually, this is one of those nonsense questions that begs for a non-answer. If someone has never flown on an airline, and never intends to, then why try to get status on them? If one has flown on that airline, then those flights will count toward status and the added cost to get status would be less. If one intends to fly, why not wait until those flights occur and have them count toward status? Somewhere, there may be someone deranged enough to qualify for status purely as a lark (and, if so, they will undoubtedly post here), but I doubt it.

For me, I got Platinum status once on AA (up from Gold) for $300, but I had already done substantial flying on AA that year. Theoretically, the cheapest way to status is with segment runs (I figured 3 years ago that I could make Executive Platinum on AA for $1700 without any other flying, it's probably up somewhat now, but that involved 17 days of 18 hour-per-day flying, if I wasn't crazy starting it I would be crazy by the time I finished it.

What makes sense is doing a bit extra to get status or higher status. If you normally qualify on segments, get creative on your routings and you can add 25% to your segment count. If you qualify on miles, you can add 25% to your mileage. But if so doing won't bring you to at least 80% of the amount required, I would just forget it.