Plentiful and cheap???? I see 8x57 occasionally, but plentiful and cheap are two adjectives that I would not use for a description. And, as stated, most of the surplus stuff is corrosive.
I don't shoot a lot of it anyway. I have an old 88 Mauser rebarreled to 8x57S (original bore was .318", 8x57S is .323") for the back ups, Hitler Youth, etc. And, I have an old Hakim rifle in 8x57 that I have to be careful to stay away from Turkish ammo with. The old 88 ain't too strong compared to a 98 and is really a Manlicher style action rather than Mauser. It doesn't have the gas management and extra locking back up of the 98, though when I got it I bought 400 rounds of Turkish ammo not knowing any better and it didn't blow it up. I've got dies now and can reload for ether weapon if I want to fire them for some odd reason. The 88 collects dust, but the Hakim is kinda fun and I take it to the range on rare occasion. It's quite accurate, but pretty worthless for any real use other than just fun. It weighs more than a 105 howitzer and it's longer than 16" gun on the Iowa. LOL I gave $37.50 for the old 88 Mauser and $80 for the Hakim. The attraction was the price, LOL.