One thing that new botters don't consider when starting out suicide botting is how they will get their suicide accounts. Many think they will just make the accounts, this will be impossible on a large scale. This isn't only because of the shear amount time it takes to create enough accounts but also because your IP will be flagged. This means all new accounts made on this IP will be locked (even accounts you make by hand) as soon as you get through tutorial island. You can go through the process of unlocking them but in my experience the ban rate after doing this is very high. You did allude to residential IP's which is a step in the right direction but if you can get an efficient method of botting tutorial island accounts I would just sell them to other suicide botters.
So you basically can bot the accounts on clean IPs (which can be extremely difficult to find) or buy the accounts with tutorial island already done. Clean IPs add extra cost and might get flagged aswell. Right now it looks like the price/account is 100-200k. Assuming you want to make 7.25 USD/hr (avg minimum wage in US), at 0.6M/USD, you need to make 11.9M/hour. At 50k/hr suicide bots (this would be a good suicide botting method) you would need 238 accounts running. When I did suicide botting the accounts would last 1-2 days depending on the time of week but your mileage may vary. Replacing this many accounts regularly can be very difficult. Also think about the servers and proxies required for this type of operation as they will cut into this profit. PS you want proxies to reduce the chance of all your accounts getting chain banned all at once. The benefit of suicide botting is that a lost account or even multiple lost accounts isn't a big deal and new bots can be started almost instantly.
Your second idea of doing higher requirement methods will make more gp/hr but it has its own issues. Like I mentioned before you still have to make the accounts which can be cumbersome but with the lower ban rates doing it yourself or even buying them is much more manageable. Adding membership means you have to make 5M (a bond) before the account is banned. There are way more methods available for member accounts but im going to assume 500k/hr (making ranarr poitions). That means the account needs to last 10 hours of botting just to make back the investment. After the 10th hour you'd be making about 0.3$/hr per account, which could equate to 7.25$/hr with 25 accounts. This may be way less accounts but you have much more to lose if one or multiple get banned.
I know you likely aren't trying to make 7.25$/hr from botting but it puts things it in perspective. Both options are possible, personally did suicide botting during uni because I didn't have enough money in my bank account to purchase a bond. I would suggest making a spreadsheet of all the expenses and profit you expect for each method type to see which option is the most viable for you.