Looking to create a project as proof of concept, to see if it fits my needs. i am looking to create a small lab of 5 routers, by making use of old PCs and ALIX 2d13 boxes (pcengines). i cannot afford to buy 5 licenses in order to see if the project is viable or not. So i would like to ask if there is any demo license that i could use for a small period of time and then choose if i need to buy or not, please.

https://wiki.mikrotik.com/wiki/Manual:License
https://wiki.mikrotik.com/wiki/Manual:CHR#Free_licenses

In short the x86 version has a 24hr demo (level 0) or a very limited demo (level 1.) The CHR has a free version, limited to 1mpbs/interface. Or 60 day trial mode for any CHR License Levels (P1, P10, P-Unlimited) that continues to work afterward, but is not upgrade-able after the trial period.

Look for the used hardware, 4xx routerboards can be had for next to nothing (with L3 or L4 licenses), also often DOM modules or CF cards with Mikrotik license on them are available for cheap (they can even be used in modern server, using IDE to SATA adapter... it's the license that matters).