I am ignorant on how to choose a cloud provider and I hope you could provide me with a guideline or share your experience. B2 charges $12/2TB whereas Google drive $10/2TB. I notice that iDirve is much cheaper, 5TB for $70 for the 1st year and $99.5 after that. iDrive can also backup gamil/calendar/contact (not sure if it can be included in the 5TB).
I also remember reading iDrive's upload/download speed is reasonable. Would you recommend iDrive?
Is cost the only consideration?
Also what is the difference of using backup service provided by a cloud provider such as Backblaze vs paying for 2TB of storage and then use ARQ? The former can be done inexpensively, why bother to use ARQ+2TB?
My GoogleDrive is AU$125pa which is only slightly more than half B2 when you take exchange rate and GST(VAT) into account. GoogleDrive prices do fluctuate - I took a deal. B2 only charges for actual space occupied whereas GoogleDrive is for potential space - so will be a bit cheaper if, for example, you only use 1.5TB.
I have doubts about iDrive. From functionality perspective it suffers from being mostly non-Mac - like Backblaze Computer Backup. In my testing some years ago, the speed (up and down) was very poor from Australia and that ruled it out. I saw complaints about speed getting worse after some time and/or as storage built up (but I have no evidence of that).
As with Backblaze you need to distinguish between iDrive (consumer/computer backup) and eDrive (S3 compatible storage like Backblaze B2).
Cost is not the only consideration, think of:
Reputation of provider,
Support (low cost > low support),
Durability usually expressed as 99.99..9% and frequently not mentioned for consumer storage (like OneDrive),
Functionality when looking at personal/consumer targeted product.
Up and down speed, particularly if distant from servers.
I have already indicated that I consider Arq much better Mac backup than Backblaze Personal Backup (same goes for iDrive) based on functionality. And you have the choice of storage provider from AWS (expensive but enterprise quality) to STORJ. And I am prepared to pay the cost of Arq (if need be) as well as "good enough" storage.
You need to try some of these services. Nearly all offer some kind of trial - either time limited (e.g. 30 days) or storage limited (e.g. 10GB).
Disclaimer re cost of Arq: I purchased in the early days when lifetime (my lifetime) licenses were offered, so no ongoing cost.