I enchanted a batch of 90 diamond pickaxes.
All enchants were between level 54-60.
The results were as follow listed in order of value/ease of sale.
High Demand-Quick Sell
UB3/For3/Eff5- 5
UB3/For3/Eff4-4
UB3/Eff5-8
UB3/For3-3
Some Demand-2-3 day sell time
For3/Eff4-8
For3/Eff4-3
Clearance-Still have majority
Eff4-12
Eff5-11
For3-6
UB3/For2-1
For2/Eff4-3
Sold for less then materials/1 week
UB3-26
but Its the only fair way for Enchanters to not spam enchants 24/7
That is a 270 diamond investment on my part.
Now factor in the amount of time I spent grinding xp, marketing, taking inventory, negotiating deals, porting to and from spawn to my inventory.
All for a 22.2% return that is not a consistent.
Your success in earning c with enchanting was more based on luck+return on investment+good merching.
In order to "spam enchants 24/7" you would have to have the raw materials to do so.
If you stack on 200-400xp cost per enchant.
The time investment this adds to enchanting make it not worth doing.
You would be better of sticking your c in the /lottery.
Less effort and you could spend 100% of the time mining rather then selling.