I have a Nikon Buckmaster in 4X and a Weaver K4. Both are between $130 and $170 and I have used them for years with no problems.
The Buckmaster seems to have an edge on the optics, but either should do an excellent job and are very reliable. I moved my Buckmaster to my 20 gauge slug gun last fall and I was absolutely delighted at how precise the W & E adjustments were when zeroing in. At $2.50 per slug, I didn't want to play games and the the point of impact changed exactly to what I had dialed on the scope. Lightfield sabots + NEF Ultra slig barrel + Buckmaster scope.
I also have a Nikon Monarch 4X40 I purchased a couple of years ago on sale which is superb, but I believe that model is discontinued.
I believe LaOtto and I are talking about the same Weaver scope (Weaver Classic K4 in Midway's catalog. I didn't realize it was caled Classic. Good choice.)
http://www.midwayusa.com/eproductpage.exe/showproduct?saleitemid=174349ADD: Sorry the way I wrote that sentence about the Nikon Monarch. I bought the scope on sale - but I do not have it for sale. Poor choice of words on my part.