Could you provide a reference for the UC Boulder option? I've had professor pals look into this on my behalf, and the confident answer they got back is that all US accrediting bodies require a Bachelor's before entering a Master's program.

The UK option is interesting. For those curious, here's the bit explaining that they normally expect a Bachelor's but will consider experience: https://www.cs.ox.ac.uk/softeng/study/index.html

And the total cost is ~$50k: https://www.cs.ox.ac.uk/softeng/study/Fees_2022-23.pdf