a simple search on the gov.scot website states that the list of providers for PCR / LFTs can be found on the gov.uk website so not sure how you reach the conclusion that the Scottish gov are limiting the test providers and pushing the prices up. It’s the same list.
from the current guidance it’s only the red list countries that has essential reasons only. Since there are currently NO RED LIST COUNTRIES on Scotland’s nor the UK’s list travel is no longer for essential reasons only.