Mod components are rarer than cores. You can only get mod components by dismantling year 1 weapons or pay a hefty price to ada. Cores can be bought from spider plus earn 6 per week from his bounties. You can earn 3 per day from scrapper bounties, get them from completing a weekly bounty at Hawthorne. Plus you can get countless from dismantling the right year 2 gear. Plus all the curated raid weapons/Gambit prime weapons, dismantle your duplicates that's 7 cores each. When I play a lot I probably get between 30-50 cores per week. For mod components without buying from Ada, I probably get less than 5 per week.