How about putting it in the CTL as a makeable arti. 50 engineered virus,50 ship-bots,200 energy. Most low ranks don't get enough of the arti's to make many of the CTL arti's anyway which is the reason for the 50 ship-bots also coz high ranks need a way or few ways to use them.

Mutagenic cartridges shouldn't be easily obtainable; your suggested cost is far too low in my opinion. I'm by no means as experienced as others but I'd have to say... this would constitute having your cake and eating it too; too much. The truth is 50 ship bots would be easy for high rankers, you'd be de-balancing a distribution of power here and the absolute high rankers would get an even easier advantage over invading a lower ranker's planets. Engineered viruses are in low demand so using them in concept is a good idea for some artifact creation.

I'm just not sure Mutagenic Cartridges should be readily available cost-wise. It should be as it was meant to be; a fairly rare arti to get or even to manufacture.

The amounts i was using was just an example. How about 500 engineered viruses, 500 ship-bots, and 1000 energy.

TBH, should any limited arti be made aviliable otherwise, i believe they should be under increasing cost so that it is still limited in a sense.
That is to say, while it's theortically possible to get say 1000, the cost would become impractical after 50-100.

For example, the first Mutagenic can simply cost the OP price, but each additional one increase the cost by 50% of the previous.
OR, the first one cost 200 virus, 200 bot, 1000 energy and the 2nd is 2x that much, 3rd is 3x of the first and so on.

Because I feel limited artis are special in the way that they are limited and thus ppl would have to make a VERY hard decision on when to use them. And I do feel that sense of preciousness(is this a word/spelled right?) should be kept.

But I won't oppose at least an oppertunity to get more of some of the stuff

While I like the idea of being able to get more of these, and suggested it once, I believe making them a CT lab item would not be a good idea. There are players in the game that have over 40k AP/HR and beyond, imagine how many of these they could crank out with that kind of production. It would however be nice to see a new Stryll NPC that drops them with a rate about like QSE drops from a T.O. troop carrier.