I have been saying for some time that this is the flaw in the cap been used in the argument to Crete an even competition. It doesn't. If you want an even comp, the lesser lights such as Salford need to be able to over spend to attract the better players.
I'm not sure that could work though. In the example I give above, even offering 15-20% above another club may not allow a poor club to compete. So where would you stop?
What the cap does is slow growth down of a club, and I'm not too uncomfortable with that. It makes things difficult - clubs will probably have to pay over the odds for a couple of players for a couple of years and grow a touch more slowly than they would like, but as I have said before, IMHO it's right that is difficult to go from the bottom to the top.
I've seen it at my club - we started to make 'big' signings from 2004 when we moved into the new ground (if you exclude the recklessness of the Langer/Nikau/Gee era) with Martin Gleeson and the short term deal of Johns. Alongside these signings though were Danny Lima, Chris Leikvoll, John Wilshere etc. We had to build up slowly, and it (imho) made for more sustainable growth as a club.
Alongside a steady stream of signings over the years we have focused on bringing our own youth in too - we never went out and signed a dozen world class players in one go - I'm not sure we should have rules in place to allow that when in reality the Salford situation is a unique one.