Skip the high dollar units entirely. I own the taousa hand pump ( think G6 style if comparing price ) at well under $100.00 it is a value, never any issue but for some reason comes with 1 - 2 rebuild kits.
Once special note about the taousa ( and I may be spelling that incorrectly ) on mine I assembled everything hand tight.
Ya, that's it. Tightened all hose/fitting with finger tips and never any leak, nice touch.
Where's your closet airgunners ? I keep a hand pump around just to show folks they work and it's not hard work. I've been know to lend out this pump to others just starting out. It's always worth getting together with other folks esp. when statring out.
John