You need to take an objective and pragmatic view to such offerings. Sometimes it is necessary to test the waters, but to do this responsibly under constrained financial circumstances remains a challenge. This is because, still to this day, there are far too many fly by night service offerings poorly published on the internet. There is no need to mention names or point fingers. It isn’t even worth it and wastes valuable study and writing time.
Let us talk, instead, of the positive benefits of utilizing cheap papers pragmatically and responsibly. It is also an exercise in keeping to realistic expectations. The responsibility lies with you to ensure that the services on offer are reasonable and credible. Utilize your own research and reading practices to figure this out for yourself. Rocket science is not needed to discern the obvious loopholes. If an academic writing service, selling you an offer that you can afford at this time, is more than willing to share previous work done, then you may have something to work with.
Do keep in mind, however, that in many cases, the contracted writers, editors and proofreaders are already respecting their clients’ privacy and need for confidentiality. But invariably, the credible team does arrange for previous work samples to be published on their website with the kind permission of previous clients who have done this in response to a service that they were more than happy with. Depending on your year of study, do be realistic and do not expect displayed samples to always be of the same high standard that your paper requirements demand.
If there is evidence of complying with widely accepted and used academic conventions then you have something more to work with.