All three are beautiful coins but I would not grade them. I would put them in airtites at a cost of ~ 50 cents per airtite. The cost of slabbing will not likely give you a return if you were to sell them and you will lose the enjoyment raw coins provide over slabbed. Prices from NumisMedia - http://numismedia.com/rarecoinprices/fmv.shtml -revealed the following estimated values: St. Gaudens 1914-s: AU58 $2,280; MS60 $2,300; MS64 $2,610. $5 1897 Gold: AU55/AU58 $650; MS60 $660; MS63 $730. Double Eagle 1898-s: AU58 $2,290; MS61 $2,320; MS63 $2,750. I grade your coins as AU, with the St. Gauden's and Double Eagle being possible borderline MS; however, you can see that even as you get to mid-range MS, none of them jump much in value. I do not see any of the coins being high MS. So, why the above quote from jeffB after this longwinded post on why not to slab them? If I were to slab them, I would follow jeffB's advice and use ICG at $10/coin.
Thank the Lord for the "edit" feature. I corrected it and importantly, in my opinion, your correction also makes the 1898-s not a good candidate to grade.
1. Airtight are NOT. 2. If they are sonically sealed they are protected. 3. IF you do not plan to sell them in the future go with ICG but remember, if you want the most for your coins you WILL NOT GET IT WITH ICG. Stay Safe.
HOW DID YOU KNOW THEY WOULD NOT HONOR THE GRADE? DO THEY TELL YOU BEFORE YOU PAY THEM?? JUST CURIOUS, SIR, THANKS
It's not honoring the grade when dealing with a different company. It would be a cross over and they would have graded it lower
I try not to authenticate coins by images because the obverse of the 1898-S looks 100% counterfeit in your image while its revers looks 100% genuine. Note that the images appear to have been taken in different light. That "low alloy fake gold color" may help make the obverse look counterfeit. I voted keep your money to buy more gold coins.