McCoist is currently attempting to lead the Gers back into the top flight -where he hopes they will be able to challenge Celtic for the Scottish title.
But he watched international stars like Steven Davis, Allan McGregor, Steven Naismith and Stephen Whittaker quit Ibrox for nothing two years ago.
And he has predicted that significant investment will be required before the Light Blues can vie with their Old Firm rivals and compete in Europe again.
McCoist said: "If we get investment and funding, then I'd be very hopeful that we'd obviously be in the top league in another two years. We would also have a better chance of bringing in the quality of player to hopefully enable us to compete at the top level in the top league.
"But it depends on funding and investment and stability at boardroom level of course. That is vital."
McCoist added: "It's difficult to put a figure on it. But we have lost in the region of £30million worth of players.
"When you combine the valuations of the players we lost - Whittaker, Jelavic, Davis, McGregor and all the other boys - it comes to around £30million.
"If you lose that, I would think it certainly needs to get replaced.
"Some will argue it might be more than that, some might say a little bit less. But you can't lose that, not replace it and expect to compete at the top level."
McCoist met with Rangers chief executive Graham Wallace, who is currently halfway through his 120-day "restructuring project", at Ibrox yesterday.
The Rangers manager has stressed he will outline his requirements when Wallace completes his review of the company.
He said: "I don't have any doubt once he's done that review we will sit down and look longer term, in terms of players for next season, in terms of budget for next season, in terms of our scouting, in terms of Murray Park and development of football."
Wallace is almost certain to implement cutbacks as many experts have predicted Rangers will run out of money by April.
But McCoist revealed that a fully-manned scouting network will be a priority before the club return to the forefront of the Scottish game.
He added: "Scouting is an immediate concern, particularly now as we are heavily in to the rebuilding process for the club, short, middle and long-term.
"It's staggering that we don't have a scouting department but, I have to say, through no fault of Graham Wallace or anyone on the board. It's certainly not their fault but it is our problem which needs addressed."