There are a lot of variables involved. Is it cheaper? Generally, but how much do they charge. Is that FOB their farm, delivered, or delivered and spread? If you have to haul and spread it gets questionable. If you have to spread it then you need to figure your time and cost for that. But if they have spreader trucks it generally is cheaper.
Is it better? Yes, it is slow release. It doesn't lower your pH like commercial fertilizer does. And it increases your organic matter which is always a good thing. Also if when you compare cost most people will compare to the cost of commercial N,P, and K. With chicken litter you are also getting a bunch of micro nutrients tossed in for free.
For the cost comparison get an analysis on the manure. The results should tell you how many pounds of N, P, and K there is in a ton of manure. Find out the cost per pound for actual N, P, and K for commercial and compare costs.
For example if urea cost $460 a ton then the actual N is costing $0.50. If the chicken litter has 60 pounds of N per ton then the N in a ton of the litter is worth $30.00. Do the same with the P and K.
I get chicken manure (layer) for $9.00 a yard spread. They figure it is 2.2 yards per ton. So it cost me $19.80 a ton. It tests about 70 pounds of N per ton. That is about 28 cents per pound for N. About half the cost of commercial N with all the P and K being free. That is why I say generally it works real well.