When I used to use manual grease guns, I would always watch for the Lincoln cast head grease guns to go on sale at Napa. They used to be $20-$25 on sale. No idea what they run these days. I still have several that I use on rare occasions and they still work very well. Anything that was made of stamped parts or less than a cast head was avoided because they never lasted very long, no matter how fancy they were. If a tool does not last me a long time, it's costing me money.
I've been tempted to purchase a LocknLube lever gun because you can relieve the pressure if a fitting is bad and not accepting grease - this normally kills a push on type couple after a couple of bad fittings. It's tough to lay out over $100 for a manual grease gun that I won't likely use 6 times in a year. I've switched over to all pneumatic keg greasers to save time and money so the manual guns are only used in a pinch. If I was to choose a long term gun, I would certainly consider the LocknLube along side the Lincoln. If money is not an option, I would try the LnL. I have their 10ksi foot operated greaser for a specialty grease and that system works extremely well. Not cheap to purchase but it works well and the grease filler tool works well, too.
As Mike_27 mentioned, LnL couplers are the way to go. I've tried the Chinese knock-offs and they don't last anywhere near as long, maybe 6 month to a year, and can't be rebuilt. I have several LnL couplers and I usually get about 2 years use before using the rebuild kit that came with it. Typically, push on couplers last me 2 weeks to 2 months if I'm lucky, sometimes 2 days. Time is money and the math is pretty easy on this one. $30 with a rebuild kit and no hassles for a year or more - to me, that makes good logical sense.
