@Jim248
Consider what a typical fully-furnished rental would cost in your area, factor in generous usage of electricity+water+internet (and cable if you provide) and then whatever amenities you provide in addition (clean sheets/towels each week? any regular cleaning?)
You need to charge WAY MORE than what people would pay as rent.
So it's not about a monthly discount - it's about what is your payout total is. If you set a high nightly rate, you can afford to apply a higher monthly discount. If your monthly rates are minimal, then no monthly discount would be needed. IMO, it's a matter of perception. I offer a 20% monthly discount, but I intentionally set a higher than average nightly rate, I have no cleaning fee, and I make sure the total host payout (after the discount and Airbnb host fees are deducted) end up to be what I need it to be to make hosting worth while. - I could very easily adjust the nightly rate down or up and offer either a 10% monthly discount or 30% monthly discount.... and still be paid the same.
FYI, I used to host a lot of long-term exchange student guests (in my shared home private room & bath listing), staying anywhere from 1 month to 5 months. I factored in what it would cost them to stay at the school dorm vs. a roommate situation (usually with a local student) vs. short-term rental of a furnished studio apartment. I also looked at prices of nearby guesthouses and motels/budget hotels. Then I priced myself to be competitive enough but also making sure I was covering the costs of hosting a guest while securing a profit margin to make the extra work worth it.
And as @Huma0 says....... ignore Airbnb's price tips..... they really are completely ridiculous.