Would I be able to....

[caniverous toilet]

...Buy things off of Steam even though I would pay with a UK Debit card? Because I want Gmod 10, but I can't find where to buy it when it's not in dollars.

[Scornic]

If I'm not mistaken, Steam is a computer game thing, and this is a question, meaning this should be in Computer Help forum, instead of Irrelevance.

[Mr. Anderson]

10 USD.

kthx

[Chimpy]

...Buy things off of Steam even though I would pay with a UK Debit card? Because I want Gmod 10, but I can't find where to buy it when it's not in dollars.

Yes, I used a UK debit card and it worked fine.