I don’t think modern Raspberry pi’s make much sense unless you are using GPIOs or really need the low power consumption. The 3 and the 4 were OK price wise but the pi 5 is quite close to all these N100 mini computers and they are a lot more performance and expansion compared to a raspberry pi 5 and still quite low power.

Either a Topton or similar N100 based machine or a mini PC second hand is the way to go at the ~$100 mark. The mini PC will be faster and probably more expandable and cheaper but also more power consumption.