I have had always success with sprouting fenugreek seeds that were bought as a spice. And an Indian friend of mine regularly grows fenugreek for leaves from the seeds bought for cooking. The seeds sold for cooking are whole (intact) seeds - they are quite hard and therefore difficult to break and damage. But I can not really say what percentage of the seeds sprouted - it probably would have been higher if I had bought seeds that were labeled for sprouting - but for me it was satisfactory.
With most plant species the germination success gets lower with time. The seeds meant for sprouting have therefore often a germination success rate estimation on the label. And the manufacturers might therefore put more care into supplying fresher seeds and seeds of the same "age" to be able to guarantee that success.
I have never heard of anyone selling toasted fenugreek seeds (accept maybe if it has been some spice mix that already underwent some kind of tempering).
I think sprouts in general are not very traditional elements of North African or Middle Eastern cuisine, where fenugreek is used as seed or less commonly as leaves. Fenugreek sprouts might be found more in Indian cooking (where sprouts, micro greens and fenugreek leaves are used), or in more "hippy" / healthy-bowls styles of cooking.
And of course the seeds sold for sprouting can naturally be also used as a spice, but they might be sometimes a bit more expensive (and I guess that differences in strength of the flavor could also be found - so that the sprouting ones could maybe sometimes be milder / less flavorful).
Anyway ... you can use them definitely as a spice, as sprouts, micro greens, or grow them into bigger plants and use the leaves.
I would be a bit suspicious of the quality of the seeds in the big package if they are sold for super cheap ... but they might be totally fine.
