How far are you planning on carrying a 80+mm scope? Lots of weight saving in a 60mm size.
The KOWA 663 and 661 Prominars are a great lightweight option too, I love mine, I got rid of my Swaro 65 once I got the KOWA. There is also the 77 series Kowa Prominar that is phenomenal if you want one in-between the 88mm and the 66mm.If you want a large, heavier scope that gives up nothing optically to just about anything, try the Kowa Prominar 88. Compares directly with the Swaro 85. Can be had in your budget. For a smaller, more packable scope, the Swaro 65 is tough to beat for an all around scope.