Greetings, Brother / Sister!
Both indicate hard work to become rich. With both positions wealth will not come easily. HPS Maxine wrote that those millions for the Saturn in 2th house come only with hardest work, dedication, building everything from zero. Saturn is about laying foundation to serious business.
Higher planet in 8th is about power including financial and spiritual one, ruling other people's money. Both planets usually tend to stay unrealized in this world thus turn problematic. Both need conscious sublimation into the right cause.
As far as Neptune i.e. spirituality is heavily concerned, do as many wealth workings as possible to sublimate this energy into wealth / donation cause, if you wish it to be sublimated into this path. And try to find the affair / business to make you rich. Maybe asking Gods to guide you to such affair. Neptune always shows that spirituality is concerned and if it is not consciously directed into the right Neptunian cause, such as spiritual workings, it might go into the wrong one, such as all kind of all kind of financial frauds.
Neptune in 8th can be used not only for money, money is but one example, but as far as I see you mean you have these planets somehow connected? Are they in opposition? If not, then you do not need to worry about it. You can sublimate 8th Neptune in any sphere concerning spiritual working with extreme power, be it financial, spiritual, physical or state governmental power. If yes, then see the above, plus you still are free to sublimate Neptune in its own path as well. 2th is what you invest in: Saturn shows serious business, responsibility, no wonder it tends to build millionaires.
