I consider myself a power Office 365 user. I am an accountant and I have some very complex financial models in Excel. Lookups, Pivot tables galore. There are only two people in the office with a Mac. I have a 16GB M1 MBA that I bought last year that replaced a 2016 15" MBP. The M1 MBA is around twice a fast as the MBP that it replaced. It runs the financial models well, much better than my work colleagues how are running Windows and Microsoft 365 on two years old Intel PC Laptops.
My advice if you want to save money is get a M1 MBA base model and upgrade the RAM to 16GB. If you prefer working on a larger screen get an external monitor. I use a 35" widescreen LG monitor and its a great setup as the monitor has a USB C connecter that plugs into the MBA and charges it as well as drives the LG Screen. That screen was £500 in the UK. That screen may be overkill for what you need, the Base MBA with 16GB RAM is £1199 in the UK.
I am also running the Beta ARM version of Windows 11 through parallels and that runs pretty well as well. I have got Office 365 for Windows set up on Windows Arm and it runs well, although I don't really use it. The Mac version does everything I need it to. However I can remember a few years ago before Microsoft really brought the Mac version of office up to scratch it was better to run Office on a virtual PC than use the Mac Version. Thankfully I don't need to do that any more as the Mac Version of Excel is now multi threaded.
My advice if you want to save money is get a M1 MBA base model and upgrade the RAM to 16GB. If you prefer working on a larger screen get an external monitor. I use a 35" widescreen LG monitor and its a great setup as the monitor has a USB C connecter that plugs into the MBA and charges it as well as drives the LG Screen. That screen was £500 in the UK. That screen may be overkill for what you need, the Base MBA with 16GB RAM is £1199 in the UK.
I am also running the Beta ARM version of Windows 11 through parallels and that runs pretty well as well. I have got Office 365 for Windows set up on Windows Arm and it runs well, although I don't really use it. The Mac version does everything I need it to. However I can remember a few years ago before Microsoft really brought the Mac version of office up to scratch it was better to run Office on a virtual PC than use the Mac Version. Thankfully I don't need to do that any more as the Mac Version of Excel is now multi threaded.