The solo quests that max out at 4-5 generally give a fair amount of gold, but many are also highly contingent on having high search for getting the most out of them (this also holds true for some of the more common group quests at that level as well). Regardless you should still be getting a fair amount of gold out of doing them, rather than just 20-50 gp at a time. The major problem with them is that a lot of the most rewarding are take limited, so if you're constantly knocked down to low levels you can't continue to keep running them.
All of the above isn't necessarily true for anyone who cannot walk through Dunwarren, and those that are Sanctuary based have 3 low level quests that nobody else can access that are generally fairly rewarding.
In my own personal experience it is farily easy after a reset or two for a Sanctuary based PC to be level 5, have over a thousand gp, a large supply of CLW trinkets, a moderate supply of CMW trinkets and a decent variety of useful potions. All from the lowbie solo quests. Lower based PCs will generally have fewer gp, but a lot more useful potions, primarily invisibility.
All of the above isn't necessarily true for anyone who cannot walk through Dunwarren, and those that are Sanctuary based have 3 low level quests that nobody else can access that are generally fairly rewarding.
In my own personal experience it is farily easy after a reset or two for a Sanctuary based PC to be level 5, have over a thousand gp, a large supply of CLW trinkets, a moderate supply of CMW trinkets and a decent variety of useful potions. All from the lowbie solo quests. Lower based PCs will generally have fewer gp, but a lot more useful potions, primarily invisibility.
