TL;DR Try to find used BCA alpine trekkers and used skins, then upgrade as you get more into touring/backcountry and know what you like or need.
Used skins 50-100e + used BCA alpine trekkers if you can find any, got mine for 50e many years ago. Daymakers are another option but they are 300+ dollars new.
I used trekkers for few seasons, 3-6days of 300-800m vertical hiking each winter with my park skis and boots, they work well enough as i was not doing anything crazy.
2018 i did a week long touring trip to Norway, every day was around 900-1200m vertical and some of it on steeper terrain. Didnt have to turn back because of them, but their added height and fiddling with them every transistion was a bit problematic for me at some spots.
Next season i bought used frame bindings for around 100e installed them on my fischer rangers, skied on them for next 2 seasons and last season i bought used touring boots, pin bindings and skins for 320e combined, got my dads old blizzard zeroG skis for light weigth setup. Im planning on replacing frame bindings on my fischers with CAST at some point to have 2 pairs of touring skis.
It all depends where you are planning on skiing and how long or heavy days you are doing to be.
Did 1200m vertical on trekkers, 1400m vertical on frames and some couloir bootbacking. It is tiring but doable and on the way down you have proper bindings and boots, that said, i had 0 days on my frame+fischers last season after i got my pin touring set :) .
https://www.daymakertouring.com/collections/alpine-adapters/products/alpine-touring-adapters
https://www.snowcountry.eu/bca-alpine-tracker.html
**This post was edited on Jan 9th 2023 at 2:44:33pm