Both of those makers knives have appreciated many times the rate of inflation in the last thirty years. However, at the prices they now command, it is very risky business to assume that they will continue to increase in value at the same rate.
If you are really interested in knives as investment, you would be much better off finding a younger, exceptionally talented maker and investing in their knives. If you choose wisely, you may see a nice return on your investment.
Remember that the prices for both Loveless and Moran knives have more to do with Who these guys were and what they mean to the history and development of custom knives than anything related to the actual quality of their work.
I buy knives that I love for various reasons. But I never buy any knife assuming that it is going to make me money.
Paracelsus