A 4 1/2 jaw width would fall in the 75 lb range (like an Athol 624 1/2 -or- 924 1/2 or a Parker 205, for example). These should be more plentiful than the 6-8" varieties, and right in the price range you want. Still heavy, but not as hard to move around.
@Asport - Those OC White Fixtures have...