.
While I agree that it would be better to look at a good used fixed power scope, it is possible to pick up a new scope for under $100 IF you find them on sale or specials. For a 8x57 rifle, a good 4 power scope would suit most hunting or shooting needs.
One "under the radar" scope that I am using on a couple or my .22 rimfires, and also a .243 and a .30-06 is the Traditions Silver Hunter 3x9 scope. These scopes were designed for Muzzle Loading Rifles, and what I liked about them is that they have lines (or dots in the older ones) on the vertical cross hair below the intersection of the main cross hairs. These were designed for an aiming mark at ranges from 100 to 250 yards with a .50 calibre muzzle loader, but a bit of experimentation and firing gave me an idea of the range where the bullet hit when fired. For example, at 6 power with the .22 rimifre, zeroed at 50 yards, the first dot is 72 yards, the second 96 yards, and the third is 122 yards. Good enough to say 50, 75, 100 and 125 yards on a Gopher.
Although I bought them with the idea of using them on .22 rimfires only, I just had to try one on the .243. I have fired over 500 rounds with the .243 with no problems. The one mounted on the 30-06 Swedish Mauser sporter has fired over 200 rounds so far.
The regular price on these scopes is about $110. The kicker ------ I bought the four of them at Cabelas on a half price sale, for $55 each.
Take a look at the new Redfield scopes - they have a 3x9 for about $200. There is two of them, the lower priced one made in China and the higher priced one in the Phillipines. Forget the cheaper one. Vortex Crossfire scopes are under $200 at the local gun shop. Forget about a lot of that cheap crap on E-Bay - there are even fake Leupolds made in China today. But I would look at a scope in the $200 retail range, rather than trying to get one for under $100. Get on the Internet and check around - there are some bargains out there.
.