I have heard it said on this forum many times that unless a coin is worth 150.00, the you won't come out ahead due to grading costs.
If you like losing money, ignore the rest of this 
Consider the grading companies (TPGs) are businesses:
1. Ask yourself why a business exists.
2. TPGs record/publish how many of the highest graded slabs, let's call them "money-slabs," they have assigned.
3. The less money-slabs assigned a specific coin increases the market price people pay to own one.
4. Therefore more and more people pay the companies to slab their coins hoping for a money-slab.
BTW:
5. The invention of online registry set competitions has boosted the prices of slabs considerably - another genius marketing idea.
B/c
TPG's use no verifiable scientific standards for grading, cracking out a coin and resubmitting (even to the same company) means different grades can/do result. Hence the company's profitable "re-slabbing game" exists with people re-submitting and hoping for a money-grade slab.
If you just like collecting slabs for what they are, then go for it and enjoy the slabs/hobby (including registry sets)!
But if you are asking about slabbing (and I see you have a couple similar posts) with hopes of finding good coins, slabbing, and then selling for profit, then despite youtube hype (remember people make videos there for money and want to make exciting content), there would be an awful lot of us who have been collecting for many years who would be a lot more wealthy.
Full Steps: A marketing gimmick. Search this forum to find where the FS designation, when slabs are compared, again is an inconsistent thing and a
gamble.
You do not know if it will be assigned or not. Grading companies have a terrible record for variety assignment. Just one example is int he essay in my signature showing incompetence on a rookie level for one of the easiest to see
Kennedy half varieties.
This is NOT a slam against anyone liking FS nickels (I like them.)! It is just another way of saying to always buy the coin and not the slab.
BTW - the companies will not tell you why they assign the grade/designation they do.