k-Strategy would be marry best woman possible, have a few kids (5-10), protect them from modern culture and get 25-80 high quality grand-kids.
r-Strategy would be spamming as many kids as possible. You will loose out on average quality, because the eggs will be lower quality. Also your kids won't have many kids themselves on average since they can neither enter your economic niece nor protect themselves from the current cultural corruption. However you could manage to have 100-200 children with 150-250 grandchildren.
Since r-strategy will give you low quality children and also low TFR for each child, you really have to overcompensate with quantity. The main limitation to have so many kids will be time. So you need good sourcing of women and also outsource much of the communication to employees.
You have the to find potential women earlier than other sperm donors and you have to convince women to take your sperm, by making the process easy & comfortable and giving some social proof.
Create a charity helping couples in the 3rd world with fertility issues. Hire medical sales to go from gynecologist to gynecologist to hang up an advertisement for your charity. Help 4 couples initially and then 1 couple per year financially to have kids. Document this for Facebook/Ticktock/Instagram/YT. Women will go to gynecologist, see the advertisement, go to the Facebook site and fill out the application in the hope of the charity paying for their fertility treatment. I hire a virtual assistant to process and filter the applications. Applications who would benefit from sperm will be further processed. Other applications will be asked to apply next year since the budget is already used up for this year. If the single woman / couple / lesbian is comfortable with getting a sperm donation, I pay for transport to me, I pay for medical testing, I pay for hotel, etc. She will be accompanied by a hired sales girl to got to restaurants / zoo / swimming / etc. The purpose will be to mate guard and make the woman feel comfortable with her decision, take pictures for social media, etc. After giving birth I send a nurse to the woman to help her for one month and take a DNA sample to test for paternity. The pictures will be then processed for a different set of social media accounts not belonging to the charity.
The value proposition for the potential mum will be, she doesn't have to pay for any medical bills, she will have a nice time and she gets the child she desires. Get a baby, no effort and no money required.
100 children would be roughly 1 impregnation per month for 10 years. 3 times a month I would visit a hotel with a nurse and make a artificial Insemination.
Salary per month in the Philippines is 200-400 EUR, making hiring people affordable.Pay some money for advertisement. Maybe you could manage this operation with 5000€ a month, which would be 600.000 EUR after 10 years.
What could possibly go wrong?