What is cheaply? Cheaper than White?
I don't disagree that you keep throwing darts at the board in regards to QB's....but I don't think you throw those darts in hopes of finding a back-up, you're hoping to unearth the next Purdy or Brady to hopefully supplant your current QB. Backup QB's are a dime a dozen for what you're hoping they'll provide, which is someone who can win 1-2 games if your starter misses 3-4 games. Ultimately you want to keep your starter healthy and never see your backup QB. If you have a backup QB that can take over, if you lose your starter for the year, and get your team to the playoffs and possibly the SB....you won't have that backup the next year. Depth at QB is great, but the reality is, your backup will be quite a drop-off from your starter, regardless of how hard you try to get quality depth. If he's not, you trade one of them for assets to improve your team in other areas.....or pray to God you hit the lottery in the next draft because both your QB's suck.