Not to worry. That's a very common problem w/ Land Cruisers and other 4x4's. It's likly just grease leaking around the cv boot clamps. Some guys have reclamped with a hose clamp to fix. Others have pulled the axle and put new boots on all together. I would guess a mechanic would charge $200 or so to put new boots on and less to just replace the clamps. You can also buy a needle injector for your grease gun and pump some fresh grease in there before reclamping. A full rebuild with new grease and boots is best, but may be costly as the axle has to be pulled. I would estimate 3-4 hours labor maybe??
Bottom line, don't worry about it. You can fix if you want, or just drive the heck out of it and don't worry about it. Unless you are off road in mud/water alot, you will probably never have any issues with the axles. Most people don't even know they are leaking.
Hope that rambling helps!!