On AliExpress you can buy 30 colors pla for 7€ as a set for 3d printing pens.

Nope, it is not significant. The only thing that really stands out is the runout sensor with loading function function that is sold for 2.0, if you dont need that, print ninjaflex 24/7 and your 1.5 has no direct issues there is no need to upgrade.

If those 2 are from the same job its either a sagging gantry on an ender or the bed/mesh is not tilted properly or not meshed/leveled properly. Check squareness and sagging gantry, then check mesh/level after.

Oups misread that

Just jumping in here, the first layer does look kinda shitty, at least theres a lot of room for improvement.

Here’s a little guide to improve on a multitude of things by teaching tech.

Cool cura feature thou :)

Im using a filament fuser 3d printed. Try looking for filament fuser/welder/connector on thingi or any other page. There are also professional solutions on the market but diy cheap printed thing works flawlessly for me.

I simply attach it to other filament leftovers and print stuff with it where color does not matter.