Overpaying at the deadline is usually a bad idea. You get more long term value out of the picks. And unless you are actually winning the Super Bowl, which most don't, then you blew all that value on half a season and you are left with nothing. Instead, bank your long term value over and over again until you are ahead of the 8 ball. Consider selling at a deadline sometime to accrue extra assets in a year where you don't have real title hopes.
I don't think the Cowboys are particularly elite and I probably wouldn't buy.
But if they are gonna, it needs to be for an Amari Cooper-like player who signs an extension so we can at least claim we got some term of service and not just 10 games.