I think the priority of other positions should take precedence over WR. I mean, what's currently the strongest position on the team? I'd say WR is your #1 spot, so why put so much energy into improving it? Nobody is doubting that Moss could be an improvement over a #3 WR (well, maybe some are), but why even bother to spend the money? Are you really going to see the return on your investment?
Strongest position on this roster is at defensive tackle, not wide receiver.
What money is being spent? Burleson is set to make $4M this year. If Moss agreed to a two year, incentive laden contract we could reduce that number by half, and likely see more production. It's not about spending more money, it's about getting more bang for our buck and reducing the cap hit from the #2 receiver position. That would open up more money to be spent elsewhere.
I think there are other areas for improvement that would suffer greatly if the powers-at-large were to seek a deal to sign Moss, notably LB. I've read more LB complaints on this board than any position in the last 4 months. Tackling seems to be a recurring issue.
Again, a good GM seeks to improve their roster where ever possible, even at spots considered to be strengths. Why? Injuries. Having stellar starters with little quality depth will kill a team in no time. And reducing money in one spot opens up money to be spent at another to add either a quality starter or quality depth. That's how strong teams are built. The Packers were decimated by injuries in 2010, but won the Super Bowl because of the quality depth they had.