I voted 20-40k
Usually when I'm in lights I save up...
Once I unlock the Scats/heavy lights (heavier lights?

) at spawn rank I'll share with players needing a hand or players I know that will expand exponentially on my gift....and it's usually the last little 'hump' in between lights and the more expensive mediums that is the most trouble for me, so I always appreciate a hand out to bump me into mediums...so I try to do the same...
Once I get into mediums I'm good....either too rank up fast or just bank up ridiculous amounts and give it away...heavies are meh, I like 'em sometimes but I definitely prefer the medium bracket...
It is hilarious giving a clan bro 130k when they ask for 5k....sometimes a lucky random pubber
There is a point though were I don't given anything out (unless it's a CJW) because I need every penny if I'm still in a medium to buy something bigger if I get tore up by something....at a certain point mediums aren't always viable, and you need something bigger. But you can push it awhile with a healthy reserve....