I have not looked for one lately.
Outfits like Springfield Sporter,J+G sales,Numrich,Sarco,etc usd to sell a variety of them.Generally $59 to $89
I bought a 1927 Polish 98 small ring long action for $25 once at a gun show.
A friend bought a bulk buy of Mexican 98 small ring short actions many years ago.I got in on a few,for real cheap.
I think those days are gone,just like the $75 M-1 carbines. You might find a Crotchety Old Goober who stil lhas a few stashed .
These days,the price of an original MilSurp rifle is up there with used commercial rifles.It just does not make sense to tear down a milsurp rifle.
By the time you alter a bolt,drill and tap,install a Timney,buy and fit a barrel,rent or buy a reamer,maybe...find an old,seasoned,properly laid out stock blank,or a good,quality foam core glass/kevlar stock,and the little things like a scope safety ,Accra-glass,guard screws,stock finishing ,sandpaper and other shop supplies,bluing or cerro safe,.....
Even doing all of your own work,if you have a lathe,mill,etc,and if you had a $100 action,you will have over $500 in a milsurp sporter build.If you are paying for gunsmith work,I'm thinking you'll break $1000.
When you are done,its a reworked milsurp.It might be a fine hunting rifle,but if you need to sell it some day,prepare to cry.The market is not kind.
You might be able to take advantage of that fact.
Beware,workmanship varies,but you might pick up a rifle some other guy spent $1000 to build for $250.
Better yet,look to old big box private brand rifles,Like Western Field,JC Higgins,Ted Williams,etc.Many of these were built on FN commercial Mausers. Good guns!
A few years back,there were a number of Husqvarna rifles imported to USA,These were built on milsurp 98's,but factory built.I'm sure they have dried up,but they might be sitting on some pawn shop rack.
You are asking a question a lot like "Where can I get a Ford Mustang or a Camaro or a Falcon or Chevy 2,or a dang old Hippy Van?"
Followed by wistful,nostalgic stories of what once was.