If you want an idea i started from 0 in 2023 and now i get 285 issues (with almost all the keys included) i spent 1590 dollars that, i am under 250 dollars to finish. And more i live in Switzerland so i have to buy to international and paid expensive delivery. Considering that i think you can get the full run for like 1300-1400 dollars if you do some good deals.
My best advice is to no be feared about buy some expensive big lots, often you see some lots with big keys included and a great number of other books, you do the math and realize the offer is always better. If you just pick each issues you will pay the real prices for keys and 3 for conventional issues, is too much...
So buy some great lots to disgorge and after complete the hole