Your question is almost impossible to answer. The 'difference' depends on a lot things, amongst others exact material grade (LTCS, as you mention, has different grades), product form and/or product size (is it a small or big vessel/pump/frame/boiler/whatever), location (ability to source material), design code, preservation (LTCS may require coating whereas 304L may suffice with pickling & passivating), etc..
Even if you can specify all these things, it still can be tricky to determine the difference. There simply are too many unknowns.