There are other reasons for the price of 303 sporters to go up.
Inflation for one.
With the desirability of the Lee Enfields going up as collectables and the realization of how good these firearms really are, there are more people now that want them. Some of those sporters are also very well done and make excellent, accurate rifles for casual hunters/shooters.
It just isn't Lee Enfields either. When was the last time you checked out the price of a Springfield or Remington 1903 variant that was sporterized.
As mentioned above, milsurp firearms are drying up all over the world. Recently Johnone described an incident in Greece where a bunch of new in crates Greek Mannlicher rifles were relegated to the scrap heaps. It was cheaper to just destroy them than to sell them into the surplus market and go through all of the international bureaucratic paperwork at border crossings.
There may still be warehouses of these firearms out there, many in as new or FTRed condition but the UN is making sure they won't be made available to the plebes of the world.
If you're serious about wanting to own one or several of these historical pieces, quit procrastinating and get one while they are still relatively affordable.
The notion that "surplus" means cheap or junk, is foolish and many are finding out the hard way that they have missed the boat.
The RC Mausers were shunned when they first came out. I bought several for $150 each. They were very nice as I had the privelege of picking through several dozen for the better ones. I had the intentions of turning them into cheap sporters. The actions were all perfect and ideal for such projects. Luckily, time and common sense took over when I realized how limited the seemingly abundant supply of these rifles would turn out to be.
Life goes on, if we don't keep up with the changes we get left behind.
One thing that really blows me away, is the price of RC P38s. They are more expensive than excellent condition vet bringbacks. Excellent holsters are more expensive than the pistols. I wonder how expensive the RC P08 pistols will be, when and if the Russians realize how desireable these pistols are to western collectors?